Unless indicated otherwise, or the context otherwise requires, references herein to “ArcelorMittal”, “we”, “us”, “our”, “ArcelorMittal Group”, “Group” and the “Company” or similar terms are to ArcelorMittal S.A consolidated with its subsidiaries. References to “ArcelorMittal S.A.”, “ArcelorMittal parent” or “parent of ArcelorMittal” are to ArcelorMittal S.A., formerly known as Mittal Steel Company N.V. (“Mittal Steel”), having its registered office at 24-26, Boulevard d’Avranches, L-1160 Luxembourg, Grand Duchy of Luxembourg, and, where the context requires, its consolidated subsidiaries. References to the “ArcelorMittal group” and the “Group” are to ArcelorMittal and its consolidated subsidiaries.Luxembourg. ArcelorMittal’s principal operating subsidiaries, categorized by reporting segment and location, are listed below.

In addition, unless indicated otherwise, or the context otherwise requires, references in this annual report to abbreviations or terms shown below have the following definitions:

This annual report contains the audited consolidated financial statements of ArcelorMittal and its consolidated subsidiaries, including the consolidated statements of financial position as of December 31, 20182019 and 2017,2018, and the consolidated statements of operations, other comprehensive income, changes in equity and cash flows for each of the years ended December 31, 2019, 2018 2017 and 2016.2017. ArcelorMittal’s consolidated financial statements were prepared in accordance with International Financial Reporting Standards (“IFRS”) as issued by the International Accounting Standards Board (“IASB”).

The financial information and certain other information presented in a number of tables in this annual report have been rounded to the nearest whole number or the nearest decimal. Therefore, the sum of the numbers in a column may not conform exactly to the total figure given for that column. In addition, certain percentages presented in the tables in this annual report reflect calculations based upon the underlying information prior to rounding and, accordingly, may not conform exactly to the percentages that would be derived if the relevant calculations were based uponon the rounded numbers. This annual report on Form 20-F includes net debt and operating working capital, which are non-GAAP financial measures. ArcelorMittal believes net debt and operating working capital to be relevant to enhance the understanding of its financial position and provides additional information to investors and management with respect to the Company’s operating cash flows, capital structure and credit assessment. Non-GAAP financial measures should be read in conjunction with and not as an alternative for, ArcelorMittal’s financial information prepared in accordance with IFRS. Such non-GAAP measures may not be comparable to similarly titled measures applied by other companies.

Not applicable.

The following tables present selected consolidated financial information of ArcelorMittal as of and for the years ended December 31, 2019, 2018, 2017, 2016 2015 and 2014,2015, prepared in accordance with IFRS as issued by the IASB. This selected consolidated financial information should be read in conjunction with ArcelorMittal’s consolidated financial statements, including the notes thereto, included elsewhere herein.

Not applicable.

Not applicable.

As a producer and seller of steel, the Company is directly exposed to fluctuations in the market price for steel, iron ore, coking coal and other raw materials, energy and transportation. In particular, steel production consumes substantial amounts of raw materials including iron ore, coking coal and coke, and the production of direct reduced iron, the production of steel in EAFs and the re-heating of steel involve the use of significant amounts of energy, making steel companies dependent on the price of and their reliable access to supplies of raw materials and energy. Although ArcelorMittal has substantial sources of iron ore and coal from its own mines (the Company’s self-sufficiency rates were 49%52% for iron ore and 12% for PCI and coal in 2018)2019), it nevertheless remains exposed to volatility in the supply and price of iron ore and coking coal given that it obtains a significant portion of such raw materials under supply contracts from third parties.parties. For additional details on ArcelorMittal’s raw materials supply and self-sufficiency, see “Item 4.B—Information on the Company—Business overview—Mining products—Other raw materials and energy”.

An increase in exports of low-cost steel products from developing countries, along with a lack of effective remedial trade policies, could depress steel prices in various markets globally, including in ArcelorMittal’s key markets. Conversely, ArcelorMittal is exposed to the effects of import tariffs, other trade sanctions, barriers and protectionist policies more generally due to the global nature of its operations. Various countries have instituted, and may institute trade sanctionsimport tariffs and barriers that could, depending on the nature of the measures adopted, adversely affect ArcelorMittal’s business by limiting the Company’s access to or competitiveness in steel markets. While such protectionist measures can help the producers in the adopting country, they may be ineffective, raise the risk of exports being directed to markets where no such measures are in place or are less dissuasive and/or result in retaliatory measures. For example, the adoption of protectionist measuressteel and aluminum tariffs in the United States in March 2018 in the form of Section 232 25% import tariffs on all steel product categoriesunder "Section 232" led to a surge of steel imports in other markets (for example, exports from Turkey in particular surged in Europe in the first half of 2018) and consequently provoked retaliatory safeguard measures by other countries, (theincluding the European Commission, Turkey,Union, Canada and Mexico. With regard to ArcelorMittal in particular, the Eurasian Economic Union all adopted provisional safeguard measurespositive effect of the Section 232 tariffs in the form of tariff quotasUnited States in 2018 on its U.S. sales was partially offset by the negative effects on ArcelorMittal’s exports from Canada and Mexico into the United States. While on May 17, 2019, the United States, Canada and Mexico reached an agreement to remove the 25% tariffs on aluminum and steel products, during 2018). See “Item 4.B—Information on the Company—Business overview—Government Regulations—Foreign trade” for more information. It isit remains unclear what impact these and other protectionist measures (including additional European import quotas adopted in August 2019) will have in 2019,and whether

In addition, certain of these joint ventures and associates are currently experiencing, or may in the future experience, difficult operating conditions and/or incur losses. Difficult operating conditions in joint ventures and associates in which ArcelorMittal has invested may expose it to loss of its investment, requirements for additional investments or calls on guarantees. For example, ArcelorMittal’s joint venture Al Jubail’s financial situation has been negatively impacted by a slower than expected ramp-up of operations and required further funding in 2018 and 2019 and may require further funding.additional funding in the

As of December 31, 2019, a trust (HSBC Trustee (C.I.) Limited, as trustee), of which Mr. Lakshmi N. Mittal, Mrs. Usha Mittal and their children are the beneficiaries (referred to as the "Significant Shareholder"), beneficially owned (within the meaning of Rule 13d-3 under the Securities Exchange Act of 1934, as amended) shares amounting (when aggregated with ordinary shares of ArcelorMittal and options to acquire ordinary shares held directly by Mr. and Mrs. Mittal) to 382,277,751 shares, representing 37.41% of its contractors are represented by labor unionsArcelorMittal’s outstanding shares. As a result, the Significant Shareholder has the ability to significantly influence the decisions adopted at the ArcelorMittal general meetings of shareholders, including matters involving mergers or other business combinations, the acquisition or disposition of assets, issuances of equity and are covered by collective bargainingthe incurrence of indebtedness. The Significant Shareholder also has the ability to significantly influence a change of control of ArcelorMittal. For further information on the Company’s major shareholders, see “Item 7.A—Major shareholders and related party transactions—Major shareholders”.

ArcelorMittal could become subject to rationalize operations through temporary or permanent idling and/or closure of plants. These initiatives have in the past and mayunidentified liabilities in the future, leadsuch as those relating to protracted labor disputesuncontrolled tailings breaches or other future events or to underestimated emissions of polluting substances. For example, the failure of a tailings ponds dam at ArcelorMittal’s mines could cause significant damage, including death, injury and political controversy.environmental harm. While the Company carries out assessments of its facilities, it cannot guarantee that failures or breaches of a tailings ponds dam will not occur in the future. In February 2019, the Company decided as a precautionary measure to implement its plan to evacuate the community situated downstream of its dormant Serra Azul tailing dam with a 5.8Mm³ tailings volume in Brazil. The decision was based on an updated site-based assessment following recent incidents in the Brazilian mining sector pending further testing and implementation of any necessary mitigation measures. In August 2019, ArcelorMittal Burns Harbor experienced a failure at the pump station for the blast furnace process water recycle system, which is believed to have contributed to the reported exceedances of Ammonia-N and cyanide at two outfalls and impacted aquatic wildlife near those outfalls. See "Item 4.B—Information on the Company—Business overview—Sustainable development—Management Theme #4: Environment—Responsible water use".

Products: ArcelorMittal produces a broad range of high-quality finished and semi-finished steel products (“semis”). Specifically, ArcelorMittal produces flat steel products, including sheet and plate, and long steel products, including bars, rods and structural shapes. In addition, ArcelorMittal produces pipes and tubes for various applications. ArcelorMittal sells its steel products primarily in local markets and through its centralized marketing organization to a diverse range of customers in approximately 160 countries including the automotive, appliance, engineering, construction and machinery industries. The Company also produces various types of mining products including iron ore lump, fines, concentrate and sinter feed, as well as coking, PCI and thermal coal.

Automotive focus: ArcelorMittal has a leading market share in its core markets in the automotive steel business and is a leader in the fast-growing advanced high strength steels segment. ArcelorMittal is the first steel company in the world to embed its own engineers within an automotive customer to provide engineering support. The Company begins working with original equipment manufacturers (“OEMs”) as early as five years before a vehicle reaches the showroom, to provide generic steel solutions, co-engineering and help with the industrialization of the project. In November 2016, ArcelorMittal introduced a new generation of advanced high strength steels, including new press hardenable steels and martensitic steels. Together, these new steel grades aim to help automakers further reduce body-in-white weight to improve fuel economy without compromising vehicle safety or performance. In November 2017, ArcelorMittal launched the second generation of its iCARe® electrical steels. iCARe® steel grades play a central role in the construction of electric motors. See­ “Item 4.B— Information on the Company—Business overview—Competitive strengths—Research and development” below for further detail.

Mining Value Chain: ArcelorMittal has a significant portfolio of raw material and mining assets. In 2018,2019, approximately 49%52% of ArcelorMittal’s iron-ore requirements and approximately 12% of its PCI and coal requirements were supplied from its own mines. The Company currently has iron ore mining activities in Brazil, Bosnia, Canada, Kazakhstan, Liberia, Mexico, Ukraine and the United States. The Company currently has coal mining activities in Kazakhstan and the United States.

ArcelorMittal’s principal investments, acquisitions and disposals, and other key events that occurred during the year ended December 31, 20182019 are summarized below. For further information on ArcelorMittal’s ongoing capital expenditure projects, see “Item 4.D—Information on the Company—property,Property, plant and equipment—Capital expenditure projects”. During 2019 and early 2020, ArcelorMittal completed several debt financing and repayment transactions see “Item 5.B—Operating and financial review and prospects—Liquidity and capital resources” and note 6.1.2 to the consolidated financial statements.

ArcelorMittal is a public limited liability company (société anonyme) that was incorporated for an unlimited period under the laws of the Grand Duchy of Luxembourg on June 8, 2001. ArcelorMittal is registered at the R.C.S. Luxembourg under number B 82.454.

ArcelorMittal’s success is built on its core values of sustainability, quality and leadership and the entrepreneurial boldness that has empowered its emergence as the first truly global steel and mining company. Acknowledging that a combination of structural issues and macroeconomic conditions will continue to challenge returns in its sector, the Company has adapted its footprint to the new demand realities, intensified its efforts to control costs and repositioned its operations to outperform its competitors.

Against this backdrop, ArcelorMittal's strategy is to leverage four distinctive attributes that will enable it to capture leading positions in the most attractive areas of the steel industry value chain, from mining at one end to distribution and first-stage processing at the other:

On February 5, 2016, the Company announced its Action 2020 plan, which represents a strategic roadmap for each of ArcelorMittal’s main business segments. The Action 2020 plan goes over and above the Company’s ongoing management gains plan and seeks to deliver real structural improvements unique to ArcelorMittal’s business. The Action 2020 plan targets to improve the Company’s operating income by $3 billion, absent any recovery in steel spreads and raw materials prices from the levels at the beginning of 2016. The Company is approximately two-thirdsin the fourth year of the way along theits five year Action 2020 journey, but made limitedwith ongoing progress achieved in 2018 with $0.42019 of $0.7 billion in cost and product mix improvements, largelypartly offset by volume reductions duelower volumes driven by macroeconomic headwinds, for a net improvement of $0.4 billion. The savings achieved in 2019 relate mainly to operational disruptions.the transformation program in Europe for optimization of maintenance activities, purchase initiatives, reduction of fuel and energy usage and improvement of yield in several sites. The savings achieved in 2019, together with the improvements achieved up through 2018 takes the cumulative progress to $2.0 billion since 2016, entirely on cost and mix improvements.

Some of the key segment initiatives included in the Action 2020 plan at the time of launch, and which the Company continues to pursue are as follows:

As shown by the following graph, ArcelorMittal has a diversified portfolio of steel and mining products to meet a wide range of customer needs across many steel-consuming sectors, including automotive, appliance, engineering, construction, energy and machinery and via distributors.

ArcelorMittal is the largest producer of steel in North and South America and Africa and the fifth largest steel producer in the CIS region. It is also the largest steel producer in the EU, with significant operations in France, Germany, Belgium, Spain, Italy, Luxembourg Poland, the Czech Republic and Romania.Poland. In addition, many of ArcelorMittal’s operating units have access to developing markets that are expected to experience, over time, above-average growth in steel consumption (such as Central and Eastern Europe, South America, India, Africa, CIS and Southeast Asia).

The Company sells its products in local markets and through a centralized marketing organization to customers in approximately 160 countries. ArcelorMittal’s diversified product offering, together with its distribution network and research

The Company has iron ore mining activities in Brazil, Bosnia, Canada, Kazakhstan, Liberia, Mexico, Ukraine and the United States. The Company has coal mining activities in Kazakhstan and the United States. ArcelorMittal’s main mining

The Company’s long-life iron ore and coal reserves provide a measure of security of supply and an important natural hedge against raw material volatility and global supply constraints. The mining business is managed as a separate segment which enhances ArcelorMittal’s ability to optimize capital allocation.

Long-term contracts add to the stability of the business. ArcelorMittal has built close relationships with its customers, often working with them at the vehicle design stage. These relationships are founded on the Company’s continuing investment in R&D and its ability to provide well-engineered solutions that help make vehicles lighter, safer and more fuel-efficient.

ArcelorMittal has a leading market share in its core markets and is a leader in the fast-growing advanced high strength steels segment. In 2012,2010, ArcelorMittal initiated a development effort for hybrid vehicles with aof dedicated S-in motion® project.engineering projects. Its S-in motion® line of solutions (C(B,C&D car segments, SUV, pick-up trucks, light commercial vehicles, truck cabs)cabs, Hybrid vehicles, Battery Electric Vehicles) is a unique offering for the automotive market that respond to OEMs’ requirements for safety, fuel economy and reduced CO2 emissions. By utilizing advanced high strength steels promoted in the S-in motion® projects, OEMs can achieve significant weight reduction using the Company's emerging grades solutions such as Fortiform®, the Company's third generation Advanced High Strength Steels ("AHSS") for cold forming, or Usibor® 2000 and Ductibor® 1000, the Company's latest AHSS grades for hot stamping. Further S-in motion® projects are currently underway for electrical cars in the C segment as well as for the plug-in hybrid C-segment with results expectedhave been completed in 2019. There are multiple specificities for Battery Electric Vehicles: shorter front module, necessity to protect batteries against crash, lowering of the center of gravity, huge additional weight due to batteries etc. All these specificities require to rethink crash management. S-in Motion BEV for SUV is a catalogue of steel solutions adapted to this new type of vehicles. Advanced and especially Ultra high strength steels, innovative press hardened steels, laser welded blanks are especially highlighted as key solutions for an optimal performance (safety/weight). The growth of various types of electric vehicles will impact design and manufacturing. For instance, new large mass batteries change the mass distribution of a vehicle and impact the design and manufacturing of the chassis and wheels. Battery protection provides another example: both battery boxes and body structure have to protect batteries in the event of a crash. For these specific cases, AHSS and especially Ultra High Strength Steels will play a major role. AHSS products are among the most affordable solutions on the market for these specific applications. In a context where the supply of electric vehicles, and especially Battery Electric Vehicles ("BEVs") are expected to grow quickly, new projects have been launched to address these new trends. For further details on the new products under development, see "Item 4.B—Information on the Company—Business overview—Competitive strengths—Research and development.”development”.

In parallel, ArcelorMittal continues to promote intensively the second generation of its iCARe® electrical steels. iCARe® steel grades play a central role in the construction of electric motors which are used in BEVs, hybrid vehicles ("HV"), plug in hybrid vehicles ("PHEV") and mild hybrid vehicles ("MHV"). This new iCARe® generation features optimized mechanical, magnetic and thermal properties of the steel as compared to the first generation of iCARe® electrical steels.

The Company announcedremains focused on achieving its Action 2020 plan (see “Item 4.B—Information on the Company––Business overview––Business strategy”)targets, which targetstargeted an improvement in operating income of $3 billion absent any recovery(see “Item 4.B—Information on the Company—Business overview—Business strategy”). In response to an unfavorable market environment, ArcelorMittal reduced production during the second half of 2019 across all geographies in steel spreadsorder to address overcapacity and raw materials prices fromunprofitable volumes. Since market conditions have frustrated the levels atCompany’s efforts to increase volumes by the beginning of 2016.