As filed with the Securities and Exchange Commission on September 19, 201720, 2019

RegistrationNo. 333-220235333-                

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Amendment No. 1

to

FORMS-4

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

OCEANFIRST FINANCIAL CORP.

(Exact name of registrant as specified in its charter)

975 HOOPER AVENUE, TOMS RIVER, NEW JERSEY 08753110 WEST FRONT STREET, RED BANK, NEW JERSEY 07701

(732)240-4500

(Address, Including Zip Code, and Telephone Number, Including Area Code, of Registrant’s Principal Executive Offices)

Christopher D. Maher

President and Chief Executive Officer

975 Hooper Avenue110 West Front Street

Toms River,Red Bank, New Jersey 0875307701

(732)240-4500

(Address, Including Zip Code, and Telephone Number, Including Area Code, of Agent for Service)

Copies to:

Approximate date of commencement of proposed sale to the public: As soon as practicable after this Registration Statement becomes effective and the conditions to the closing of the mergerTransactions described herein have been satisfied or waived.

If the securities being registered on this Form are to be offered in connection with the formation of a holding company and there is compliance with General Instruction G, check the following box:  ☐

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act of 1933, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act of 1933, check the following box and list the Securities Act of 1933 registration statement number of the earlier effective registration statement for the same offering.  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, anon-accelerated filer, or a smaller reporting company or emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer”filer,” “smaller reporting company” and “smaller reporting“emerging growth company” in Rule12b-2 of the Exchange Act. (Check one):

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.  ☐

If applicable, place an X in the box to designate the appropriate rule provision relied upon in conducting this transaction:

Exchange Act Rule13e-4(i) (Cross-Border Issuer Tender Offer)  ☐

Exchange Act Rule14d-14d-1(d) 1(d) (Cross-Border Third-Party Tender Offer)  ☐

The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933, as amended, or until the Registration Statement shall become effective on such date as the Commission, acting pursuant to said Section 8(a), may determine.

Information contained herein is subject to completion or amendment. A registration statement relating to these securities has been filed with the Securities and Exchange Commission. These securities may not be sold nor may offers to buy be accepted prior to the time the registration statement becomes effective. This document doesshall not constitute an offer to sell or athe solicitation of anany offer to buy nor shall there be any sale of these securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or from any person to whom it is unlawful to makequalification under the securities laws of any such offer or solicitation in such jurisdiction.

PRELIMINARY — SUBJECT TO COMPLETION — DATED SEPTEMBER 19, 201720, 2019

Prospectus		Proxy Statement
		Prospectus

MERGER AND SHARE ISSUANCE PROPOSED — YOUR VOTE IS VERY IMPORTANT

Dear Stockholder:Two River Shareholders:

On June 30, 2017,August 9, 2019, OceanFirst Financial Corp., a Delaware corporation (which we refer to as “OceanFirst”), Sun Bancorp, Inc., a New Jersey corporation (which we refer to as “Sun”), and MercuryHammerhead Merger Sub Corp., a New Jersey corporation and a wholly-owned subsidiary of OceanFirst (which we refer to as “Merger Sub”), and Two River Bancorp, a New Jersey corporation (which we refer to as “Two River”), entered into an Agreement and Plan of Merger (which we refer to as the “merger agreement”) that provides for the combination of OceanFirst and Sun.Two River. Under the terms of the merger agreement, (i) Merger Sub will merge with and into SunTwo River (which we refer to as the “first-step merger”), with SunTwo River continuing as the surviving corporation in the first-step merger and as a wholly-owned subsidiary of OceanFirst, (ii) immediately following the completion of the first-step merger, SunTwo River will merge with and into OceanFirst (which we refer to as the “second-step merger” and, together with the first-step merger, the “integrated mergers”), with OceanFirst continuing as the surviving corporation in the second-step merger, (we refer to the surviving corporation following the second-step merger as the “combined company”), and (iii) immediately following the completion of the integrated mergers, Sun NationalTwo River Community Bank, a nationalNew Jersey charterednon-member bank and a wholly-owned subsidiary of SunTwo River (which we refer to as “Sun National“Two River Bank”), will merge with and into OceanFirst Bank, National Association, a national banking association and a wholly-owned subsidiary of OceanFirst (which we refer to as “OceanFirst Bank”), with OceanFirst Bank being the surviving bank in such merger (which we refer to as the “bank merger” and, together with the integrated mergers, the “Transactions”).

At the effective time of the first-step merger (which we refer to as the “effective time”), each outstanding share of the common stock, no par value, $5.00 per share, of SunTwo River (which we refer to as “Sun“Two River common stock”), except for certain shares of SunTwo River common stock owned by SunTwo River as treasury shares, any subsidiary of Two River, OceanFirst or any subsidiary of OceanFirst (other than any such shares held in employee benefit plans or related trust account, managed accounts, mutual funds, or otherwise held in a fiduciary capacity or as a result of debt previously contracted) (which we refer to as the “exception shares”), will be converted into the right to receive either:

Holders of Sun common stock will have the right“cash consideration”), and 0.6663 shares (such number being referred to electas the “exchange ratio” and such shares being referred to receiveas “stock consideration” and together with the cash consideration, or the stock consideration, subject to the allocation and proration provisions“merger consideration”) of the merger agreement. The merger agreement provides thatcommon stock of OceanFirst, par value $0.01 per share (which we refer to as “OceanFirst common stock”), together with cash in lieu of fractional shares, if any.

Although the aggregate amount of cash consideration will not exceed the product of (x) $3.78 and (y) the total number of shares of SunOceanFirst common stock issued and outstanding immediately priorthat holders of Two River common stock will be entitled to receive as the effective time.

Thestock portion of the merger consideration is fixed, the market value of such shares (and, therefore, the value of the stock considerationportion of the merger consideration) will fluctuate with the market price of OceanFirst common stock and will not be known at the time that holders of Sun common stock (which we refer to as the “Sun shareholders”)Two River shareholders vote on the first-step merger. However, as described in more detail elsewhere in the accompanying proxy statement/prospectus, under the terms of the merger agreement, if the average of the daily closing prices of OceanFirst common stock over a specified period of time prior to the receipt of all requisite regulatory approvals for the Transactions (disregarding any applicable waiting period) decreases below certain specified thresholds, Two River would have a right to terminate the merger agreement, unless OceanFirst elects to increase the exchange ratio, which would result in additional shares of OceanFirst common stock being issued. Based on the $24.88 volume weighted-average$23.14 closing price of OceanFirst common stock on the NASDAQ for the five trading day period ending on and including September 15, 2017Global Select Market (which we refer to as the “assumed“Nasdaq”) on August 8, 2019, the last full trading day before the public announcement of the Transactions, the per share value of the merger consideration was equal to $20.79. Based on the $[●] closing price of OceanFirst share closing price”)common stock on the Nasdaq on [●], 2019, the latest practicable trading day before the printing of this jointthe accompanying proxy statement/prospectus, the per share value of the merger consideration was equal to $23.32 (and the aggregate value of the merger consideration was equal to approximately $449.5 million), which includes the value of the stock portion of the merger consideration and the cash portion of the merger consideration.$[●]. Based on an assumedthe exchange ratio of 0.9403 (which was based on the assumed OceanFirst share closing price) and the number of shares of SunTwo River common stock outstanding as of September 15, 2017 (which includes[●], 2019, the maximum number of shares of Sun common stock underlying Sun’s restricted

stock awards and restricted stock award units as of September 15, 2017), the maximum number of OceanFirst common stock estimated to be issuable at the effective time is 18,646,027.[●].We urge you to obtain current market quotations for OceanFirst (trading symbol “OCFC”) and SunTwo River (trading symbol “SNBC”“TRCB”)..

OceanFirst will hold a special meeting of its stockholders (which we refer to as the “OceanFirst special meeting”) in connection with the issuance of the shares of OceanFirst common stock representing the stock consideration (which we refer to as the “OceanFirst share issuance”). At the OceanFirst special meeting, the holders of OceanFirst common stock (which we refer to as the “OceanFirst stockholders”) will be asked to vote to approve the OceanFirst share issuance. Approval of the OceanFirst share issuance requires the affirmative vote of a majority of the total votes cast by the OceanFirst stockholders at the OceanFirst special meeting.

SunTwo River will hold a special meeting of its shareholders (which we refer to as the “Sun special meeting”) in connection with the first-step merger.Transactions. At the Sun special meeting, SunTwo River shareholders will be asked to vote to approve the merger agreement, and the transactions contemplated thereby, and related matters as described in this jointthe accompanying proxy statement/prospectus. Under New Jersey law, and Sun’s organizational documents, approval of the merger agreement requires the affirmative vote of at least a majority of the votes cast at the special meeting by Sun shareholdersthe holders of shares of Two River common stock entitled to vote at the Sun special meeting.

The OceanFirst special meeting willis scheduled to be held on October 25, 2017[●], 2019 at 975 Hooper Avenue, Toms River, New Jersey 08753,[●], at 6:00 p.m. local time. The Sun special meeting will be held on October 24, 2017 at 350 Fellowship Road, Suite 101, Mt. Laurel, New Jersey 08054, at 10:00 a.m.[●] local time.

The SunTwo River board of directors unanimously recommends that SunTwo River shareholders vote “FOR” the approval of the merger agreement and the transactions contemplated thereby, including the first-step merger, “FOR” the Sun merger-related compensation proposal and “FOR” the Sun adjournment proposal.other proposals to be considered at the special meeting.

The OceanFirst board of directors unanimously recommends that OceanFirst stockholders vote “FOR” the OceanFirst share issuance and “FOR” the OceanFirst adjournment proposal.

This jointaccompanying proxy statement/prospectus describes the Sun special meeting, the OceanFirst special meeting, the Transactions, the OceanFirst share issuance, the documents related to the Transactions and other related matters.Please carefully read thisthe entire jointaccompanying proxy statement/prospectus, including “Risk“Risk Factors,” beginning on page 27,[●], for a discussion of the risks relating to the proposed merger and the OceanFirst share issuance.Transactions. You also can obtain information about OceanFirst and Sun from documents that eachit has filed with the Securities and Exchange Commission.

Christopher D. Maher President and Chief Executive Officer and Chairman of the Board OceanFirst Financial Corp.		Thomas M. O’BrienWilliam D. Moss Chairman of the Board, President and Chief Executive Officer SunTwo River Bancorp Inc.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the securities to be issued in the first-step merger or passed upon the adequacy or accuracy of this jointthe accompanying proxy statement/prospectus. Any representation to the contrary is a criminal offense.offense.

The securities to be issued in the first-step merger are not savings or deposit accounts or other obligations of any bank ornon-bank subsidiary of either OceanFirst or Sun,Two River, and they are not insured by the Federal Deposit Insurance Corporation or any other governmental agencyagency..

The date of this jointthe accompanying proxy statement/prospectus is September 20, 2017,[●], 2019 and it is first being mailed or otherwise delivered to OceanFirst stockholders and Sunthe shareholders of Two River on or about September 22, 2017.[●], 2019.

NOTICE OF SPECIAL MEETING OF STOCKHOLDERS

To the Stockholders of OceanFirst:

OceanFirst will hold the OceanFirst special meeting at 6:00 p.m. local time, on October 25, 2017, at 975 Hooper Avenue, Toms River, New Jersey 08753 to consider and vote upon the following matters:

We have fixed the close of business on September 15, 2017, as the record date for the OceanFirst special meeting (which we refer to as the “OceanFirst record date”). Only OceanFirst stockholders of record as of the OceanFirst record date are entitled to notice of, and to vote at, the OceanFirst special meeting, or any adjournment of the OceanFirst special meeting. Approval of the OceanFirst share issuance proposal requires the affirmative vote of a majority of the total votes cast by the holders of OceanFirst common stock at the OceanFirst special meeting. The OceanFirst adjournment proposal will be approved if a majority of the votes cast by the holders of OceanFirst common stock at the OceanFirst special meeting are voted in favor of the OceanFirst adjournment proposal.

The OceanFirst board of directors has unanimously approved the merger agreement and the transactions contemplated thereby, including the integrated mergers and the OceanFirst share issuance, and unanimously recommends that OceanFirst stockholders vote “FOR” the OceanFirst share issuance proposal and “FOR” the OceanFirst adjournment proposal.

Your vote is very important. We cannot complete the integrated mergers unless the OceanFirst stockholders approve the OceanFirst share issuance proposal.

Regardless of whether you plan to attend the OceanFirst special meeting, please vote as soon as possible. If you hold stock in your name as a stockholder of record of OceanFirst, please complete, sign, date and return the accompanying proxy card in the enclosed postage-paid return envelope. If you hold your stock in “street name” through a bank or broker, please follow the instructions on the voting instruction card furnished by the record holder.

This joint proxy statement/prospectus provides a detailed description of the OceanFirst special meeting, the Transactions, the OceanFirst share issuance, the documents related to the Transactions and other related matters. We urge you to read this entire joint proxy statement/prospectus, including any documents incorporated in this joint proxy statement/prospectus by reference, and its annexes carefully and in their entirety.

BY ORDER OF THE BOARD OF DIRECTORS,

Christopher D. Maher

President, Chief Executive Officer and Chairman of the Board

NOTICE OF SPECIAL MEETING OF SHAREHOLDERS

To the Shareholders of Sun:Two River Shareholders:

Sun will hold the SunA special meeting of the shareholders of Two River Bancorp, or Two River, is scheduled to be held at 10:00 a.m.[●] local time, on October 24, 2017,[●], 2019, at 350 Fellowship Road, Suite 101, Mt. Laurel, New Jersey 08054[●] to consider and vote upon the following matters:proposals:

We have fixed the close of business on September 15, 2017,[●], 2019 as the record date for the Sun special meeting (which we refer to as the “Sun record date”).meeting. Only SunTwo River shareholders of record as of the Sun record date are entitled to notice of, and to vote at, the Sun special meeting, or any adjournment of the Sun special meeting. Under New Jersey law, and Sun’s organizational documents, approval of the Sun merger proposal requires the affirmative vote of a majority of the total votes cast by Sun shareholders entitled to vote at the Sun special meeting. The Sun merger-related compensation proposal will be approved ifleast a majority of the votes cast on such proposal at the Sun special meeting are voted in favorby the holders of such proposal.shares of Two River common stock entitled to vote at the special meeting. Approval of the compensation proposal requires the affirmative vote of at least a majority of the votes cast at the special meeting by the holders of shares of Two River common stock entitled to vote at the special meeting. The Sun adjournment proposal will be approved if athe majority of the votes cast on such proposal at the Sun special meeting are votedby the holders of shares of Two River common stock entitled to vote at the special meeting vote in favor of such proposal.

The SunOur board of directors has unanimously approved the merger agreement,Agreement and Plan of Merger, has determined that the mergersuch agreement and the transactions contemplated thereby,by such agreement, including the integrated mergers,first-step merger, are advisable, fair to and in the best interests of SunTwo River and its shareholders, and unanimously recommends that Sun shareholders vote “FOR” the Sun merger proposal, “FOR” the Sun merger-related compensation proposal and “FOR” the Sun adjournment proposal.

Your vote is very importantimportant.. We cannot complete the integrated mergersfirst-step merger unless the SunTwo River shareholders approve the Sun merger proposal.

Regardless of whether you plan to attend the Sun special meeting, please vote as soon as possible. If you hold shares of Two River common stock in your name as a shareholder of record of Sun,Two River, please complete, sign, date and return the accompanying proxy card in the enclosed postage-paid return envelope. You may also vote by telephone or through the Internet.Internet by following the instructions on the proxy card. If you hold your shares of Two River common stock in “street name” through a bank, broker or broker,other nominee, please follow the instructions on the voting instruction card furnished by the record holder.

This jointThe accompanying proxy statement/prospectus provides a detailed description of the Sun special meeting, the Transactions, the Sun merger proposal, Sun merger-related compensation proposal, the documents related to the Transactions and other related matters. We urge you to read this entire jointthe proxy statement/prospectus, including any documents incorporated in this jointthe proxy statement/prospectus by reference, and its annexes carefully and in their entirety.

BY ORDER OF THE BOARD OF DIRECTORS,

Thomas M. O’Brien

William D. Moss

Chairman of the Board,

President and Chief Executive Officer

Two River Bancorp

REFERENCES TO ADDITIONAL INFORMATION

This joint proxy statement/prospectus incorporates important business and financial information about OceanFirst and SunTwo River from documents filed with the Securities and Exchange Commission (which we refer to as the “SEC”) that are not included in or delivered with this joint proxy statement/prospectus. You can obtain any of the documents filed with or furnished to the SEC by OceanFirst and/or SunTwo River at no cost from the SEC’s website at http://www.sec.gov. You may also request copies of these documents, including documents incorporated by reference in this joint proxy statement/prospectus, at no cost by contacting the appropriateapplicable company at the following address:

You will not be charged for any of these documents that you request. To obtain timely delivery of these documents, you must request them no later than five business days before the date of yourthe special meeting. This means that OceanFirst stockholdersTwo River shareholders requesting documents must do so by October 18, 2017,[●], 2019, in order to receive them before the OceanFirst special meeting, and Sun shareholders requesting documents must do so by October 17, 2017, in order to receive them before the Sun special meeting.

You should rely only on the information contained in, or incorporated by reference into, this document. No one has been authorized to provide you with information that is different from that contained in, or incorporated by reference into, this document. This document is dated September 20, 2017,[●], 2019, and you should assume that the information in this document is accurate only as of such date. You should assume that the information incorporated by reference into this document is accurate as of the date of such document, and neither the mailing of this document to SunTwo River shareholders or OceanFirst stockholders nor the issuance by OceanFirst of shares of OceanFirst common stock in connection with the first-step mergerTransactions will create any implication to the contrary.

This document does not constitute an offer to sell, or a solicitation of an offer to buy, any securities, or the solicitation of a proxy, in any jurisdiction to or from any person to whom it is unlawful to make any such offer or solicitation in such jurisdiction. Except where the context otherwise indicates, information contained in this document regarding SunTwo River has been provided by SunTwo River and information contained in this document regarding OceanFirst has been provided by OceanFirst.

See “Where“Where You Can Find More Information”Information” beginning on page 146[●] for more details.

TABLE OF CONTENTS

i

i

ii

ii

ANNEXES

iii

QUESTIONS AND ANSWERS

The following are some questions that you, as an OceanFirst stockholder or a Sun shareholder,holder of Two River common stock (which we refer to as a “Two River shareholder”), may have about the Transactions or the OceanFirst share issuance, the OceanFirst special meeting or the Sun special meeting, as applicable, and brief answers to those questions. We urge you to read carefully the remainderall of this joint proxy statement/prospectus because the information in this section does not provide all of the information that might be important to you with respect to the Transactions the OceanFirst share issuance, the OceanFirst special meeting or the Sun special meeting, as applicable.meeting. For details about where you can find additional important information, please see the section of this joint proxy statement/prospectus entitled “Where You Can Find More Information” beginning on page 146.[●].

Unless the context otherwise requires, references in this joint proxy statement/prospectus to “OceanFirst” refer to OceanFirst Financial Corp., a Delaware corporation, and its subsidiaries, and references to “Sun”“Two River” refer to SunTwo River Bancorp, Inc., a New Jersey corporation, and its subsidiaries.

Q: What are the Transactions?

A: OceanFirst, Sun and MercuryHammerhead Merger Sub Corp., a New Jersey corporation and wholly-owned subsidiary of OceanFirst (which we refer to as “Merger Sub”), and Two River entered into an Agreement and Plan of Merger on August 9, 2019 (which we refer to as the merger agreement on June 30, 2017. The first-step merger is“merger agreement”), which provides for the first step in a seriesstrategic acquisition of transactions to combine OceanFirst and Sun, and their respective subsidiary banks, OceanFirst Bank and Sun National Bank.Two River by OceanFirst.

Under the terms of the merger agreement:

A copy of the merger agreement is included in this joint proxy statement/prospectus asAnnex A.

The integrated mergers cannot be completed unless, among other things:

In order to approve the merger agreement and the transactions contemplated thereby, including the first-step merger, Two River has called a special meeting of the Two River shareholders (which we refer to as the “special meeting”). This document also serves as a notice of the special meeting and describes the proposals to be presented at the special meeting.

In addition, this document is also a prospectus of OceanFirst that is being delivered to Two River shareholders because OceanFirst is offering shares of common stock, par value $0.01 per share, of OceanFirst (which we refer to as the “OceanFirst common stock”) approve the issuanceto Two River shareholders as a portion of the shares of OceanFirst common stockconsideration in connection with the first-step merger (which we refer to as the “OceanFirst share issuance”).

Bancorp 2007 Equity Incentive Plan (which we refer to as the “Two River equity plan”), whether vested or unvested (which we refer to as “stock options”), will be convertedcanceled, extinguished and exchanged into the right to receive an optionamount of cash (without interest) equal to purchase athe product of (a) the aggregate number of shares of Two River common stock issuable upon exercise of such stock option and (b) the excess, if any, of (i) the sum of (A) the cash consideration and (B) the product of the exchange ratio and the VWAP of OceanFirst common stock (rounded downon the Nasdaq for the five full trading days ending on the last trading day preceding the closing of the integrated mergers, over (ii) theper-share exercise price of such stock option.

Restricted Stock: Upon approval of the merger agreement and the transactions contemplated thereby by the Two River shareholders at the special meeting, pursuant to the nearest whole share) determinedterms of the Two River equity plan, each restricted stock granted by multiplying (i) the numberTwo River in respect of shares of SunTwo River common stock subject to such Sun stock optionthat is granted under the Two River equity plan and is outstanding immediately prior to the effective time by (ii) the exchange ratio;(which we refer to as shares of “restricted stock”) will become fully vested and the exercise price perrestrictions thereon will lapse. At the effective time, each holder of a vested share of the new optionrestricted stock will be equalentitled to the quotient obtained by dividing (a)receive the per share exercise pricemerger consideration in exchange for eachsuch share of Sunrestricted stock.

Employee Stock Purchase Plan: Effective as of October 15, 2019, Two River will terminate the Two River Bancorp Employee Stock Purchase Plan (which we refer to as the “ESPP”), pursuant to which eligible employees could purchase Two River common stock subject to such Sun option by (b) the exchange ratio (rounded up to the nearest whole cent).through payroll deductions.

Q: Will the value of the merger consideration change between the date of this joint proxy statement/prospectus and the time that the first-step merger is completed?

A: Yes. Any changes inBecause the market price of OceanFirst common stock will have a corresponding effect onexchange ratio is fixed, the value of the stock consideration. In addition,portion of the merger consideration will fluctuate between the date of this proxy statement/prospectus and the closing date because the market value of the per share cash consideration is derived from the OceanFirst share closing price during a period prior to the closing, any changes in the market price offor OceanFirst common stock will also have a corresponding effect on the amount of the per share cash consideration. However, the aggregate amount of thefluctuate. The cash consideration will not exceed the product of (x) $3.78 and (y) the total number of shares of Sun common stock issued and outstanding immediately prior to the effective time.is fixed.

Q: How does the OceanFirstTwo River board recommend that I vote at the OceanFirst special meeting?

A: The OceanFirstTwo River board unanimously recommends that you vote “FOR” the OceanFirst share issuance proposal and “FOR” the OceanFirst adjournment proposal.

Q: How does the Sun board recommend that I vote at the Sun special meeting?

A: The Sun board unanimously recommends that you vote “FOR” the Sun merger proposal, “FOR” the Sun merger-related compensation proposal and “FOR” the Sun adjournment proposal.

Q: When and where areis the meetings?special meeting?

A: The OceanFirst special meeting willis scheduled to be held at 975 Hooper Avenue, Toms River, New Jersey 08753[●] on October 25, 2017,[●], 2019, at 6:00 p.m. local time.

The Sun special meeting will be held at 350 Fellowship Road, Suite 101, Mt. Laurel, New Jersey 08054 on October 24, 2017, at 10:00 a.m.[●] local time.

Q: What do I need to do now?

A: After you have carefully read this entire joint proxy statement/prospectus and have decided how you wish to vote your shares of Two River common stock, please vote your shares promptly so that your shares are represented and voted at yourthe special meeting. If you hold your shares of Two River common stock in your name as a stockholdershareholder of record, you must complete, sign, date and mail your proxy card in the enclosed postage-paid return envelope as soon as possible. Alternatively, Sun shareholdersyou may vote by telephone or through the Internet or by telephone.Internet. Information and applicable deadlines for voting Sun shares by telephone or through the Internet or by telephone are set forth in the enclosed Sun proxy card instructions. If you hold your shares in “street name” through a bank, broker or broker,other nominee, you must direct your bank, broker or brokerother nominee how to vote in accordance with the instructions you have received from your bank, broker or broker.other nominee. “Street name” stockholdersshareholders who wish to vote in person at theirthe special meeting will need to obtain a legal proxy from the institution or record holder that holds their shares.

Q: What constitutes a quorum for the OceanFirst special meeting?

A: The presence at the OceanFirst special meeting, in person or by proxy, of holders representing at leastof shares of Two River common stock entitled to cast a majority of the outstanding shares of OceanFirst common stock entitled to be votedvotes at the OceanFirst special meeting will constitute a quorum for the transaction of business at the OceanFirst special meeting. Once a share is represented for any purpose at the OceanFirst special meeting, it is deemed present for quorum purposes for the remainder of the OceanFirst special meeting or for any adjournment(s) thereof. adjournment of the special meeting.

Abstentions, and brokernon-votes, if any, will be included in determining the number of shares present at the meeting for the purpose of determining the presence of a quorum.

Q: What constitutes a quorum for the Sun special meeting?

A: The presence at the Sun special meeting, in person or by proxy, of holders representing at least a majority of the outstanding shares of Sun common stock entitled to be voted at the Sun special meeting will constitute a

quorum for the transaction of business at the Sun special meeting. Once a share is represented for any purpose at the Sun special meeting, it is deemed present for quorum purposes for the remainder of the Sun special meeting or for any adjournment(s) thereof. Abstentions and broker Brokernon-votes, if any, will not be included in determining the number of shares present at the meeting for the purpose of determining the presence of a quorum.quorum because it is expected that all proposals to be voted on at the special meeting will be“non-routine” matters (i.e., matters with respect to which banks, brokers or other nominees do not have discretion to vote shares of Two River common stock, as discussed in more detail below under the question “What is a brokernon-vote?”).

Q: What is the vote required to approve each proposal at the OceanFirst special meeting?

A:OceanFirst share issuance proposal: The merger proposal:

OceanFirst adjournment proposal:The compensation proposal:

Q: What is the vote required to approve eachThe adjournment proposal at the Sun special meeting?

A:Sun merger proposal::

Sun merger-related compensation proposal:

Sun adjournment proposal:

•

Effect of abstentions and brokernon-votes: If you mark “ABSTAIN” on your proxy, fail to submit a proxy or fail to vote in person at the Sun special meeting, or fail to instruct your bank or broker how to vote with respect to the Sun adjournment proposal, it will have no effect on the Sunvote with respect to the adjournment proposal.

OceanFirst has entered into agreements (which we refer to as the “voting and support agreements”) with (1) Bernard Brown, Sidney R. Brown, Anne Koons, Irwin J. Brown, Jeffrey S. Brown, Shirley Brown, The Bernard A. Brown 2012 Trust, Sidney & Sandy Brown Foundation, Inc., The Four B’s, Interactive Logistics, LLC, National Distribution Centers, L.P., National Freight, Inc. and Vineland Construction Co. (which we refer to collectively as the “Brown family”) and (2) WLR SBI AcquisitionCo, LLC and its ultimate controlling affiliate, WL Ross & Co., LLC (which we refer to collectively as “WLR”) (which we refer to collectively as the “Sun supporting shareholders”), who have agreed, subject to certain exceptions, to, among other things, vote the shares of Sun common stock owned beneficially or of record by each Sun supporting shareholder in favor of the merger proposal. In addition, each Sun supporting shareholder has agreed to vote against any proposal made in competition with the merger proposal, as well as certain other restrictions with respect to the voting and transfer of such Sun supporting shareholder’s shares of Sun common stock.

Based on information set forth in filings with the SEC, as of September 15, 2017, made by the Sun supporting shareholders, the Sun supporting shareholders beneficially owned, in the aggregate, 7,351,065 shares of Sun common stock (approximately 39% of the outstanding shares of Sun common stock).

Q: Why is my vote important?

A: If you do not vote, or fail to instruct your bank, broker or other nominee how to vote, it will be more difficult for OceanFirst and/or SunTwo River to obtain the necessary quorum to hold their respectivethe special meetings. If you are an OceanFirst stockholder, your failure to submit a proxy or vote in person, or failure to instruct your bank or broker how to vote, or abstention with respect to the OceanFirst share issuance proposal will not be counted as a vote cast and will have no effect on the approval of such proposal, even though such approval is a condition to the completion of the integrated mergers.meeting. If you are a SunTwo River shareholder, your failure to submit a proxy or vote in person, or failure to instruct your bank, broker or brokerother nominee how to vote, or your abstention with respect to the Sun merger proposal will not be counted as a vote cast and will have no

effect on the approval of such proposal, even though such approval is a condition to the completion of the integrated mergers. The OceanFirst share issuancemerger proposal must be approved by the affirmative vote of at least a majority of the total votes cast by the OceanFirst stockholders at the OceanFirst special meeting. The Sun merger proposal must be approved by the affirmative vote of a majority of the total votes castmeeting by the holders of Sunshares of Two River common stock entitled to vote at the Sun special meeting. The OceanFirstTwo River board unanimously recommends that the OceanFirst stockholders vote “FOR” the OceanFirst share issuance proposal and the Sun board unanimously recommends that the Sun shareholders vote “FOR” the Sun merger proposal, “FOR” the compensation proposal and “FOR” the adjournment proposal.

Q: What is a brokernon-vote?

A: A brokernon-vote occurs when a bank, broker or other nominee is not permitted to vote without instructions from the beneficial owner of the shares and the beneficial owner fails to provide the bank, broker or other nominee with such instructions. Banks, brokers and other nominees may use their discretion to vote “uninstructed” shares (i.e., shares of record held by banks, brokers or other nominees, but with respect to which the beneficial owner of such shares has not provided instructions on how to vote on a particular proposal) with respect to matters that are considered to be “routine,” but not with respect to“non-routine” matters.

All of the proposals currently scheduled for consideration at the special meeting are“non-routine” matters. If your bank, broker or other nominee holds your shares of Two River common stock in “street name,” such entity will vote your shares of Two River common stock only if you provide instructions on how to vote by complying with the voter instruction form sent to you by your bank, broker or other nominee with this proxy statement/prospectus.

Q: If my shares of Two River common stock are held in “street name” by my bank, broker or broker,other nominee, will my bank, broker or brokerother nominee automatically vote my shares for me?

A: No. Your bank, broker or brokerother nominee cannot vote your shares without instructions from you. You shouldmust instruct your bank, broker or brokerother nominee how to vote your shares in accordance with the instructions provided to you.you if you want your bank, broker or other nominee to vote your shares. Please check the voting form used by your bank, broker or broker.

Q: If I am a participant in Sun’s 401(k) Plan, how will shares owned through such plans be voted?

A: If you hold shares of Sun common stock through the Sun National Bank 401(k) Plan (which we refer to as the “Sun 401(k) Plan”), you will receive a voting instruction card for the Sun 401(k) Plan that reflects all shares you may vote under the Sun 401(k) Plan. Under the terms of the Sun 401(k) Plan, a participant is entitled to vote the shares of Sun common stock held in the Sun Bancorp, Inc. Stock Fund and credited to his or her Sun 401(k) Plan account.

Q: If I am a participant in OceanFirst’s ESOP, OceanFirst’s 401(k) Plan or Ocean Shore’s 401(k) Plan, how will shares owned through such plans be voted?

A: If you participate in the OceanFirst Bank Employee Stock Ownership Plan or the OceanFirst Bank Matching Contribution Employee Stock Ownership Plan (which we collectively refer to as the “OceanFirst ESOP”), the OceanFirst Bank Retirement Plan (which we refer to as the “OceanFirst 401(k) Plan”), or the Ocean Shore Bank Savings and Investment Plan (which we refer to as the “Ocean Shore 401(k) Plan”), which was maintained by Ocean Shore Holding Co. (which we refer to as “Ocean Shore”) prior to November 30, 2016, the date on which OceanFirst completed its acquisition of Ocean Shore (which we refer to as the “Ocean Shore acquisition”), you will receive a voting instruction form for each plan that reflects all shares that you may vote under the particular plan. Under the terms of the OceanFirst ESOP, the OceanFirst ESOP trustee votes all shares held by the OceanFirst ESOP, but each OceanFirst ESOP participant may direct the trustee how to vote the shares of OceanFirst common stock allocated to his or her account. The OceanFirst ESOP trustee, subject to the exercise of its fiduciary responsibilities, will vote all unallocated shares of OceanFirst common stock held by the OceanFirst ESOP and allocated shares for which no voting instructions are received in the same proportion as shares for which it has received timely voting instructions.

Under the terms of the OceanFirst 401(k) Plan and the Ocean Shore 401(k) Plan, respectively, a participant is entitled to provide instructions for all shares credited to his or her OceanFirst 401(k) Plan account or Ocean Shore 401(k) Plan account, as applicable. The trustee will vote all shares for which no directions are given or for which timely instructions were not received in the same proportion as shares for which voting instructions were timely received.

The deadline for returning your voting instructions is October 18, 2017.other nominee.

Q: Can I attend the OceanFirst special meeting and/or the Sun special meeting and vote my shares of Two River common stock in person?

A: Yes. All stockholders of OceanFirst andTwo River shareholders, including shareholders of Sun, including stockholders and shareholders of record and stockholders and shareholders who hold their shares “in street name” through banks, brokers nominees or any other holder of record,nominees, are invited to attend their respective meetings.the special meeting. Holders of record of OceanFirst common stock and SunTwo River common stock can vote in person at the OceanFirst special meeting and Sun special meeting, respectively.meeting. If you are not a stockholder orTwo River shareholder of record, you must obtain a proxy, executed in your favor, from the record holder of your shares of Two River common stock, such as a broker, bank or other nominee, to be able to vote in person at yourthe special meeting. If you plan to attend your special meeting, you must hold your shares in your own name or have a letter from the record holder of your shares confirming your ownership. In addition, you must bring a form of personal photo identification with you in order to be admitted. OceanFirst and Sun reserve the right to refuse admittance to anyone without proper proof of share ownership or without proper photo identification. The use of cameras, sound recording equipment, communications devices or any similar equipment during the special meetingsmeeting is prohibited without OceanFirst’s or Sun’s express written consent, respectively.prohibited.

Q: Can I change my vote?

A:OceanFirst stockholders: Yes. If you are a holder of record of OceanFirstTwo River common stock, you may change your vote or revoke any proxy at any time before it is voted by (i) signing and returning a proxy card with a later date, (ii) delivering a written revocation letter to OceanFirst’s corporate secretary or (iii) attending the OceanFirst special meeting in person, notifying the corporate secretary and voting by ballot at the OceanFirst special meeting. Attendance at the OceanFirst special meeting will not automatically revoke your proxy. A revocation or later-dated proxy received by OceanFirst after the vote will not affect the vote. OceanFirst’s corporate secretary’s mailing address is: Corporate Secretary, OceanFirst Financial Corp., 975 Hooper Avenue, Toms River, New Jersey 08753.

Sun shareholders: Yes. If you are a holder of record of Sun common stock, you may change your vote or revoke any proxy at any time before it is voted by (i) signing and returning a proxy with a later date, (including a proxy given over the Internet or by telephone), (ii) delivering a written revocation letternotice to Sun’sTwo River’s corporate secretary or (iii) attending the Sun special meeting in person, notifying the corporate secretary and voting by ballot attelephone or through the Sun special meeting.Internet prior to midnight on [●], 2019. Attendance at the Sun special meeting by itself will not automatically revoke your proxy. A revocation or later-dated proxy received by SunTwo River after the vote will not affect the vote. Sun’sTwo River’s corporate secretary’s mailing address is: Corporate Secretary, SunTwo River Bancorp, Inc., 350 Fellowship Road, Suite 101, Mount Laurel,766 Shrewsbury Avenue, Tinton Falls, New Jersey 08054.07724.

If you hold your shares of OceanFirst common stock or SunTwo River common stock in “street name” through a bank, broker or broker,other nominee, you shouldmust contact your bank, broker or brokerother nominee to change your vote or revoke your proxy.

Q: Will OceanFirst be required to submit the OceanFirst share issuance proposal to its stockholders even if the OceanFirst board has withdrawn, modified or qualified its recommendation?

Q: What are the U.S. federal income tax consequences of the integrated mergers to SunTwo River shareholders?

A: The obligations of Sun and OceanFirst to completeparties expect the integrated mergers are subject to, among other customary closing conditions described in this joint proxy statement/prospectus, the receipt by each of Sun and OceanFirst of the opinion of its counsel to the effect that the integrated mergers together will be treated as an integrated transaction that qualifies as a “reorganization” within the meaning of Section 368(a) of the Internal Revenue Code of 1986, as amended (which we refer to as the “Code”).

, and the obligation of each of OceanFirst and Two River to complete the integrated mergers is conditioned upon the receipt of an opinion of its counsel to that effect. Neither OceanFirst nor Two River currently intends to waive these conditions. Assuming that the integrated mergers qualifyare treated as an integrated transaction that qualifies as a reorganization within the meaning of Section 368(a) of the Code, Two River shareholders will generally recognize gain (but not loss) in an amount not to exceed the cash portion of the merger consideration for U.S. federal income tax purposes.

The U.S. federal income tax consequences described above may not apply to all holders of the integrated mergers to each Sun shareholder will vary depending on whether such Sun shareholder receives cash, shares of OceanFirstTwo River common stock or a combination thereof in exchange for such Sun shareholder’s shares of Sun common stock pursuant to the terms of the merger agreement.

stock. You should read the section of this joint proxy statement/prospectus entitled “U.S.“U.S. Federal Income Tax Consequences of the Integrated Mergers”Considerations” beginning on page 111[●] for a more completedetailed discussion of the U.S. federal income tax consequences ofconsiderations relating to the integrated mergers. Tax matters can be complicated and the tax consequences of the integrated mergers to you will depend on your particular tax situation. You should consult your tax advisor to determine the tax consequences of the integrated mergers to you.

Q: Are SunTwo River shareholders entitled to dissenters’ rights?

A: No. SunTwo River shareholders are not entitled to exercise dissenters’ rights in connection with the Transactions. For further information, see “The“The Transactions — No Dissenters’ Rights”Rights” beginning on page 85.[●].

Q: If I am a SunTwo River shareholder, should I send in my SunTwo River stock certificates now?

A: No. Please do not send in your SunTwo River stock certificates with your proxy. Promptly following the completion of the first-step merger, an exchange agent will send you instructions for exchanging SunTwo River stock certificates for the merger consideration. See “The Merger Agreement — Election Procedures;Conversion of Shares; Exchange of Shares”Certificates” beginning on page 89.[●].

Q: What should I do if I hold my shares of SunTwo River common stock in book-entry form?

A: You are not required to take any special additional actions if your shares of Sun common stock are held in book-entry form. Promptly following the completion of the first-step merger, shares of Sunan exchange agent will send you instructions for exchanging Two River common stock held in book-entry form automaticallyfor the merger consideration. See “The Merger Agreement — Conversion of Shares; Exchange of Certificates” beginning on page [●].

Q: What happens if the first-step merger is not completed?

A: If the first-step merger is not completed, Two River shareholders will not receive any consideration for their shares in connection with the first-step merger. Instead, Two River will remain an independent company and its common stock will continue to be listed on the Nasdaq under the symbol “TRCB.” In addition, if the merger agreement is terminated under certain circumstances, Two River may be required to pay OceanFirst a termination fee. For a more detailed discussion of the circumstances under which the termination fee will be exchanged for shares of OceanFirst common stock in book-entry form and cashrequired to be paid, please see the section of this proxy statement/prospectus entitled “The Merger Agreement — Termination Fee” beginning on page [●].

Q: What happens if I sell my shares of Two River common stock after the record date but before the special meeting?

A: The record date of the special meeting is earlier than the date of the special meeting and the date that the first-step merger is expected to be completed. If you sell or otherwise transfer your shares after the record date for the

special meeting but before the date of the special meeting, you will retain your right to vote at the special meeting, but you will not have the right to receive the merger consideration to be received by shareholders of Two River in exchange for fractionalthe first-step merger. In order to receive the merger consideration, a Two River shareholder must hold his, her or its shares if any.through completion of the first-step merger and comply with the transmittal procedures discussed elsewhere in this proxy statement/prospectus.

Q: Whom may I contact if I cannot locate my SunTwo River stock certificate(s)?

A: If you are unable to locate your original SunTwo River stock certificate(s), prior to closing, you should contact ComputerShare, Sun’sComputershare, Two River’s transfer agent, at (800) 568-3476.(781)575-4223.

Q: What should I do if I receive more than one set of voting materials?

A: OceanFirst stockholders and SunTwo River shareholders may receive more than one set of voting materials, including multiple copies of this joint proxy statement/prospectus and multiple proxy cards or voting instruction cards. For example, if you hold shares of OceanFirst common stock and/or SunTwo River common stock in more than one brokerage account, you will receive a separate voting instruction card for each brokerage account in which you hold such shares. If you are a holder of record of OceanFirst common stock and/or SunTwo River common stock and your shares are registered in more than one name, you will receive more than one proxy card. In addition, if you are a holder of both OceanFirst common stock and Sun common stock, you will receive one or more separate proxy cards or voting instruction cards for each company. Please complete, sign, date and return each proxy card and voting instruction card that you receive or otherwise follow the voting instructions set forth in this joint proxy statement/prospectus to ensure that you vote every share of OceanFirst common stock and/or SunTwo River common stock that you own.

Q: When do you expect to complete the Transactions?

A: OceanFirst and SunTwo River currently expect to complete the Transactions early in the first quarter of 2018.2020. However, neither OceanFirst nor SunTwo River can assure you of when, or if, the Transactions will be completed. The completion of the integrated mergersTransactions is subject to the fulfillmentsatisfaction or waiver of customary closing conditions, including the approval by the OceanFirst stockholdersreceipt of the OceanFirst share issuance proposal,requisite vote of the approval by the SunTwo River shareholders of the Sun merger proposal and the receipt of all requiredthe requisite regulatory approvals.

Q: What happens if the first-step merger is not completed?

A: If the first-step merger is not completed, Sun shareholders will not receive any consideration for their shares in connection with the first-step merger. Instead, Sun will remain an independent public company and its common stock will continue to be listed and traded on the NASDAQ Global Select Market (which we refer to as the “NASDAQ”). In addition, if the merger agreement is terminated in certain circumstances, a termination fee may be required to be paid by either OceanFirst or Sun. For a more detailed discussion of the circumstances under which such payments will be required to be paid, please see the section of this joint proxy statement/prospectus entitled “The Merger Agreement — Termination Fee” beginning on page 106.

Q: Whom should I call with questions?

A:OceanFirst stockholders: If you Two River shareholders who have any questions concerning the Transactions or this joint proxy statement/prospectus, would like additional copies of this joint proxy statement/prospectus or need help voting yourtheir shares of OceanFirstTwo River common stock, pleaseshould contact Investor Relations at (732)240-4500 or OceanFirst’sTwo River’s proxy solicitor, Georgeson LLC, at (888)613-9988.

Sun shareholders: If you have any questions concerning the Transactions or this joint proxy statement/prospectus, would like additional copies of this joint proxy statement/prospectus or need help voting your shares of Sun common stock, please contact Sun’s Corporate SecretaryRegan & Associates, Inc. at (800)691-7701.737-3426.