UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K/A

(Amendment No. 1)

FORM 10-K/A(Mark One)

(Amendment No. 2)

For the fiscal year ended August 31, 2014September 30, 2022

OR

For the transition period from to

Commission file number: 000-54598

Stellar Biotechnologies, Inc.

(Exact name of registrant as specified in its charter)

001-37619

Registrant’s telephone number, including area code: (805) 488-2800

Securities registered pursuant to Section 12(b) of the Act: None

Securities registered pursuant to Section 12(g) of the Act:

Common Shares, without par value

None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ¨No x

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes ¨No x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes xNo ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yesx No ¨ No¨

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K (§229.405 of this chapter) is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.x

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer”filer,” “smaller reporting company,” and “smaller reporting“emerging growth company” in Rule 12b-2 of the Exchange Act.

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 13(a) of the Exchange Act. ¨

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ¨

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statement. ¨

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ¨

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes ¨No x

The aggregate market valueAs of the voting and non-voting common shares held by non-affiliates of the registrant, computed by reference to the closing price of the registrant’s common shares on the OTCQB marketplace as of February 28, 2014,March 31, 2022, the last business day of the registrant’s most recently completed second fiscal quarter, the aggregate market value of the registrant’s outstanding common shares held by nonaffiliates was approximately $85,585,181,$35,987,404, which was calculated based on 57,827,82515,462,287 common shares outstanding as of that date, of which 12,116,971 common shares were held by nonaffiliates at $1.48 per share.the closing price of the registrant’s common shares on The Nasdaq Capital Market on such date.

As of September 1 2015,December 14, 2022, the registrant had 79,847,55019,353,351 common shares issued and outstanding.

The registrant has determined that it no longer qualified as a “foreign private issuer” under Rule 3b-4 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”). As of September 1, 2014, the beginning of the registrant’s fiscal year, the registrant is now complying with Exchange Act reporting requirements applicable to a U.S. domestic issuer.DOCUMENTS INCORPORATED BY REFERENCE: NONE

Auditor - MNP LLP; location - Toronto, Canada; PCAOB ID - 1930

Explanatory Note

EXPLANATORY NOTE

This Amendment No. 21 to the Annual Report on Form 10-K (the “Amendment No. 2”) of Stellar Biotechnologies,Edesa Biotech, Inc. (the “Company”) amends the Company’s Annual Report on Form 10-K for the year ended August 31, 2014 which wasSeptember 30, 2022 as filed with the Securities and Exchange Commission on November 14, 2014December 16, 2022 (the “Original Filing”Form 10-K”) and amended by Amendment No.1 tois being filed only for the purpose of filing Exhibit 4.11, which was inadvertently omitted from the Original Filing on November 21, 2014 (the “Amendment No.1”). The Company is filingForm 10-K.

Except as otherwise expressly noted herein, this Amendment No. 2 solely to provide Exhibit 4.1, Exhibit 4.2, Exhibit 4.3, Exhibit 4.4, Exhibit 4.5, Exhibit 4.6, Exhibit 4.7, Exhibit 4.8, Exhibit 4.9, Exhibit 4.10, Exhibit 4.11, Exhibit 4.12 and Exhibit 10.18 that were not included in the Original Filing and an updated Exhibit 31.1 and Exhibit 31.2.

This Amendment No. 2 is an exhibit-only filing. Except as described above, this Amendment No.21 does not amend, modify or update in any other information or disclosures set forth inway the Original Filing. Accordingly, this Amendment No. 2Form 10-K, nor does notit reflect any events that occurred subsequent tooccurring after the filing of the Original Filing and therefore continues to speak only as of the date ofForm 10-K. Accordingly, this Amendment No. 1 should be read in conjunction with the Original Filing.Form 10-K.

PART IV

(b)Item 15. EXHIBITS, FINANCIAL STATEMENT SCHEDULES.

(a) The following documents are filed as a part of this Annual Report:

(1) Financial Statements

The list of consolidated financial statements and notes required by this Item 15 (a) (1) is set forth in the “Index to Financial Statements” on page F-1 of this Annual Report.

(2) Financial Statement Schedules

All schedules have been omitted because the required information is included in the financial statements or notes thereto.

(3) Exhibits

The exhibits listed on the accompanying Exhibit Index below are filed as part of this Amendment No. 2Annual Report.

EXHIBIT INDEX

* All schedules and exhibits to the Share Exchange Agreement have been omitted pursuant to Item 601(b)(2) of Regulation S-K. A copy of any omitted schedule and/or exhibit will be furnished to the Securities and Exchange Commission upon request.

** The information in this exhibit (included as an exhibit to the Company’s Annual Report on Form 10-K filed with the Commission on December 16, 2022) is furnished and deemed not filed with the Securities and Exchange Commission for purposes of section 18 of the Exchange Act of 1934, as amended, and is not to be incorporated by reference into any filing of Edesa Biotech, Inc. under the Securities Act of 1933, as amended, or the Exchange Act of 1934, as amended, whether made before or after the date hereof, regardless of any general incorporation language in such filing.

@ Management contract or compensatory plan or arrangement.

+ Portions of this exhibit have been omitted pursuant to Rule 601(b)(10)(iv) of Regulation S-K.

# Previously filed.

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.