Exhibit 99.1

ArcelorMittal reports first quarter 2026 results

On April 30, 2026 - ArcelorMittal (referred to as “ArcelorMittal” or the “Company” or the "Group") (MT (New York, Amsterdam, Paris, Luxembourg), MTS (Madrid)) announced results1 for the three-month period ended March 31, 2026 (“1Q 2026”; the three month periods ended December 31, 2025, September 30, 2025, June 30, 2025 and March 31, 2025 are respectively referred to as “4Q 2025”, “3Q 2025”, “2Q 2025” and “1Q 2025”).

1Q 2026 key highlights:

Safety focus: Protecting employee health and safety is a core Company value. The multi-year safety transformation continues to deliver measurable improvements, with LTIFR improving to 0.45x in 1Q 2026 from 0.63x in 1Q 2025

Delivering structurally improved margins: The Group's results continue to demonstrate resilience, reflecting the benefits of the strategic investment program, continued asset optimization and diversified market exposures. Net income in 1Q 2026 was $0.6 billion (basic EPS of $0.76/share)

Operational momentum: Record iron ore production and shipments in Liberia and a return to normalized operating levels in North America

Seasonal investment in working capital: Net cash used in operating activities was slightly negative, reflecting a typical seasonal working capital investment (composed of an outflow for inventories of $334 million, an outflow of trade accounts receivable of $1,291 million and an inflow for trade payables of $101 million, for a $1.5 billion investment in working capital). As of March 31, 2026, gross debt amounted to $13.7 billion, while cash and cash equivalents amounted to $4.4 billion, resulting in net debt of $9.3 billion4.As of March 31, 2026, the Company also benefited from $5.5 billion of available credit lines7.

Consistent cash generation, supporting balanced capital allocation and continued growth investment: Over the past 12 months, the Company invested $4.6 billion in capital expenditures (including strategic capital expenditures of $1.5 billion), returned $0.7 billion to shareholders (comprised of dividends of $535 million and share buybacks in the amount of $168 million, and allocated $0.2 billion to M&A

Capital return policy is creating significant value for shareholders: The Company paid its first quarterly interim dividend of $0.15 per share in March 2026, as part of a proposed annual dividend of $0.60 per share. The Company will continue to return a minimum of 50% of post-dividend free cash flow to shareholders through share buybacks. The fully diluted share count has been reduced by 38% since September 20205

Strategic focus:

Well positioned to benefit from a balanced and fair European steel market: The Company believes that CBAM (which now imposes a carbon cost on imports), together with the recently agreed tariff rate quota (TRQ) trade tool (expected to be effective from July 1, 2026), structurally resets the outlook for the European steel industry. Lower imports will lead to higher capacity utilization, restoring profitability and returns on capital to healthy, sustainable levels. ArcelorMittal is well positioned to capture the volume upside through: improved utilization of its existing operating capacity; restart of idled blast furnaces (Fos (France) & Dabrowa (Poland) currently in preparation); and the commissioning of the new Gijon EAF and expanded EAF capacity at Sestao Strategic growth projects have good momentum and support higher profitability and return on capital employed: 1Q 2026 capital expenditures of $1.3 billion include $0.2 billion payment on signing new Mineral Development Agreement in Liberia11.

2026 capital expenditure guidance remains unchanged at $4.5 billion-$5.0 billion and now includes $1.7-$2.0 billion of strategic capital expenditures on high growth projects6. Strategic capital expenditure projects now include the recently approved electric arc furnace at Dunkirk and previously announced “decarbonization” EAF investments at Sestao and Gijón

Financial highlights (on the basis of IFRS1):

Commenting, Aditya Mittal, ArcelorMittal Chief Executive Officer, said:

“Performance in the first quarter was resilient despite the unsettled backdrop in the Middle East with profitability reflecting the benefits of our global diversified asset portfolio and the consistent application of our strategy. We also continued to improve our safety performance with the lowest quarterly LTIFR in the history of the Group, showing the tangible results of our sustained focus in this area.

The fundamentals of the business have improved over the past three months, driven in particular by the favourable structural reset in the European policy environment, including CBAM and the new tariff rate quota (TRQ) which is expected to significantly reduce imports into Europe from July 1. ArcelorMittal is well positioned to capture this upside through existing capacity and by re-starting idled capacity. In Europe, this will result in higher domestic capacity utilization and restore profitability and return on capital employed to healthy, sustainable levels.

This will be also an important year for the Company’s strategic growth projects, which reflect the depth of the Company’s opportunity set across diverse growth vectors. Our investments include the expansion of AM/NS India’s plant in Hazira, the ramp-up of mining in Liberia, the ramp up of the new EAF at Calvert to full capacity, as well as various opportunities related to the energy transition. We are also pleased that we have been able to take final investment decision on the new EAF in Dunkirk, supported by various policy initiatives at the European and French levels.

We remain confident in ArcelorMittal’s prospects for the balance of the year, with the expected favourable impacts of new policy including a materially improved pricing and volume environment.”

Safety and sustainable development

Health and safety:

Protecting employee health and well-being is a core value of the Company. The Group’s multi-year safety transformation continues to deliver measurable improvements, with LTIF rate improving to 0.45x in 1Q’26 (from 0.63x in 1Q’25).

In 2026, the program entered its implementation and scale-up phase, with a strong focus on strengthening execution discipline and delivering consistent, high-quality safety performance across all regions through the safety roadmaps. Efforts have centered on reinforcing key enablers such as health and safety leadership capabilities, robust risk management, process safety management, and effective contractor integration. Together, these actions contribute to achieving our overarching ambition of zero fatalities and serious injuries through sustained improvement.

For further details on the progress to date on our safety transformation program, see the 2025 Sustainability report available on the Company's website.

Own personnel and contractors – Lost time injury frequency rate

Sustainable development highlights:

Analysis of results for 1Q 2026 versus 4Q 2025

Sales increased by 3.2% to $15.5 billion in 1Q 2026 as compared to $15.0 billion in 4Q 2025, primarily reflecting higher average steel prices.

Operating income increased to $0.8 billion in 1Q 2026 as compared to $0.3 billion in 4Q 2025. 4Q 2025 had included $105 million of restructuring costs in Europe, $28 million related to Sustainable Solutions, and a non-cash loss of $61 million arising from the sale of ArcelorMittal Zenica and Prijedor in Bosnia.3 Excluding these charges, the improvement in operating income was driven by improved performance in the North America segment.

Depreciation cost for 1Q 2026 was $749 million, lower than $856 million in 4Q 2025 which was impacted by certain assets reaching end of life. 12M 2026 depreciation guidance remains unchanged at approximately $3.0 billion.

Foreign exchange and other net financial charges amounted to $80 million in 1Q 2026, lower than $450 million in 4Q 2025, primarily reflecting lower foreign exchange charges. The prior period also included a cost of $0.1 billion related to the extension of the mandatory convertible bond10.

Net interest cost increased to $133 million in 1Q 2026 as compared to $91 million in 4Q 2025, primarily due to higher gross debt and lower interest income.

Income tax expense of $136 million in 1Q 2026 compares with an income tax benefit of $201 million in 4Q 2025. 4Q 2025 was impacted by recognition of deferred tax assets following revised expectations of future profitability, primarily in Europe.

Net income in 1Q 2026 increased to $575 million (EPS of $0.76/sh) compared with $177 million (EPS of $0.23/sh) in 4Q 2025, primarily on account of higher deferred tax benefits partially offset by higher foreign exchange and other net financial charges. Net income in prior periods reflected the incurrence of certain deferred tax asset and related deferred tax expense impacts ($273 million in 4Q 2025 and $228 million in 2Q 2025).

Net cash used in operating activities in 1Q 2026 amounted to $9 million and includes a $1.5 billion seasonal investment in working capital (composed of an outflow/inflow for inventories of $334 million, an outflow of trade accounts receivable of $1,291 million and an inflow] for trade payables of $101 million, for a $1.5 billion investment in working capital). Capital expenditures totalled $1.3 billion for 1Q 2026 (including a $0.2 billion payment on signing new Mineral Development Agreement in Liberia)11. Gross debt increased to $13.7 billion as of March 31, 2026, compared to $13.4 billion as of December 31, 2025, while cash and cash equivalents decreased to $4.4 billion as of March 31, 2026, compared to $5.5 billion as of December 31, 2025, resulting in an increase in net debt to $9.3 billion as of March 31, 2026, as compared to $7.9 billion on December 31, 20254.

Analysis of operations

North America

Crude steel production increased by 18.3% to 2.1Mt in 1Q 2026, as compared with 1.8Mt in 4Q 2025, primarily driven by the successful restart of the Mexico Long products blast furnace following preventive maintenance.

Sales increased by 8.3% in 1Q 2026 to $3.3 billion, as compared to $3.0 billion in 4Q 2025, primarily reflecting higher steel shipments (+5.2%) and higher average steel selling prices (+3.5%).

Operating income improved to $206 million in 1Q 2026 as compared with an operating loss of $21 million in 4Q 2025, driven mainly by a positive price-cost effect and higher steel shipments.

Brazil9

Sales in 1Q 2026 decreased by 3.2% to $2.8 billion as compared to $2.9 billion in 4Q 2025, driven by lower steel shipments (-8.8%), largely reflecting seasonality and timing of slab export volume, partially offset by higher average steel selling prices (reflecting a richer mix).

Operating income was broadly stable at $223 million in 1Q 2026 as compared to $229 million in 4Q 2025, primarily due to lower steel shipments, partially offset by a richer mix (lower slab exports).

Europe

Crude steel production totaled 6.8Mt in 1Q 2026, representing a 6.8% increase compared to 6.4Mt in 4Q 2025. Production in 1Q 2026 nevertheless remained impacted by ongoing maintenance ahead of planned restarts in 2Q 2026. Compared to 1Q 2025, crude steel production was also impacted by the sale of the company’s Bosnian operations.

Sales increased by 10.6% to $7.4 billion in 1Q 2026 as compared to $6.7 billion in 4Q 2025, primarily reflecting higher steel shipments (+8.1%), with Flat products up 12.1% and Long products down 2.1% and higher average steel selling prices.

Operating income in 1Q 2026 was $239 million as compared to $49 million in 4Q 2025, with the benefits of higher steel shipments offset by a negative price cost effect including the impact of reduced free CO2 allocations. With CBAM in place, the additional CO2 cost is expected to be recovered via steel prices from 2Q 2026 onwards. 4Q 2025 had been impacted by impairment charges of $32 million, restructuring costs of $105 million and a $61 million final non-cash charge on the sale of ArcelorMittal Zenica and Prijedor (Bosnia).

Sustainable Solutions

Sales in 1Q 2026 were broadly stable at $2.6 billion as compared to 4Q 2025.

Operating income improved to $69 million in 1Q 2026 from an operating loss of $10 million in 4Q 2025, which included $28 million of restructuring costs and impairments of $17 million. The improvement in operating performance excluding these charges reflected improved performance of the downstream businesses.

Mining

Note: Mining segment comprises iron ore operations of ArcelorMittal Mines Canada (AMMC) and ArcelorMittal Liberia.

Sales in 1Q 2026 were broadly stable at $0.9 billion as compared to 4Q 2025.

Iron ore production totalled 9.7Mt in 1Q 2026, 3.2% lower versus 10.1Mt in 4Q 2025, driven by seasonally lower volumes at ArcelorMittal Mines Canada (AMMC) offset by higher output in Liberia. Liberia delivered another record quarter for iron ore production and shipments. The continued concentrator capacity ramp-up is expected to support higher sinter feed shipments with higher price realizations. Liberia shipment guidance remains unchanged at >18Mt in 2026.

Operating income increased to $215 million in 1Q 2026 as compared to $198 million in 4Q 2025, reflecting lower depreciation partially offset by higher freight costs.

India and JVs

Income from associates, joint ventures and other investments declined to $177 million in 1Q 2026, as compared to $206 million in 4Q 2025, due to weaker Chinese investee performance partly offset by stronger AMNS India results.

ArcelorMittal has investments in various joint ventures and associate entities globally. The Company considers AMNS India (60% equity interest) joint venture to be of particular strategic importance, warranting more detailed disclosures to improve the understanding of its operational performance and value to the Group.

AMNS India

Sales increased by 1.6% to $1.6 billion in 1Q 2026 as compared to 4Q 2025, driven by higher average steel selling prices offset in part by 12% decrease in steel shipment volumes due to planned maintenance.

Operating results in 1Q 2026, reflected a positive price-cost effect, partially offset by lower steel shipment volumes compared to 4Q 2025.

Recent development

ArcelorMittal Condensed Consolidated Statements of Financial Position1

ArcelorMittal Condensed Consolidated Statements of Operations1

ArcelorMittal Condensed Consolidated Statements of Cash flows1

Appendix 1: Capital expenditures1

Appendix 2: Debt repayment schedule as of March 31, 2026

As of March 31, 2026, the average debt maturity is 7.5 years.

Appendix 3: Reconciliation of gross debt to net debt

Appendix 4: Terms and definitions

Unless indicated otherwise, or the context otherwise requires, references in this earnings release to the following terms have the meanings set out next to them below:

Apparent steel consumption: calculated as the sum of production plus imports minus exports.

Average steel selling prices: calculated as steel sales divided by steel shipments.

Cash and cash equivalents: represent cash and cash equivalents, restricted cash and short-term investments.

Capital expenditures: represents the purchase of property, plant and equipment and intangibles. The Group’s capital expenditure figures do not include capital expenditures at the JVs level (i.e. AM/NS Calvert until June 18, 2025 and AMNS India).

Crude steel production: steel in the first solid state after melting, suitable for further processing or for sale.

Depreciation: refers to amortization and depreciation.

EPS: refers to basic or diluted earnings per share.

Free cash flow (FCF): refers to net cash provided by operating activities less capital expenditures less dividends paid to minority shareholders. The term free cash outflow is used when the difference is negative (i.e. negative free cash flow)

Foreign exchange and other net financing income/(loss): include foreign currency exchange impact, bank fees, interest on pensions, impairment of financial assets, revaluation of derivative instruments and other charges that cannot be directly linked to operating results.

Gross debt: long-term debt and short-term debt.

Impairment items: refers to impairment charges net of reversals.

Income from associates, joint ventures and other investments: refers to income from associates, joint ventures and other investments (excluding impairments and exceptional items, if any).

Iron ore reference prices: refers to iron ore prices for 62% Fe CFR China. Pricing is generally linked to market price indexes and uses a variety of mechanisms, including current spot prices and average prices over specified periods. Therefore, there may not be a direct correlation between market reference prices and actual selling prices in various regions at a given time.

Kt: refers to thousand metric tonnes.

LTIF: refers to lost time injury ("LTI") frequency rate equals lost time injuries per 1,000,000 worked hours (own personnel and contractors) and includes fatalities; an LTI is an incident that causes an injury that prevents the person from returning to his/her next scheduled shift or work period.

Mt: refers to million metric tonnes.

Net debt: long-term debt and short-term debt less cash and cash equivalents (including cash and cash equivalents held as part of assets held for sale)

Net interest expense: includes interest expense less interest income.

Operating results: refers to operating income/(loss).

Operating segments: North America segment includes the Flat, Long and Tubular operations of US, Canada and Mexico; and also includes all Mexico mines. The Brazil segment includes the Flat, Long and Tubular operations of Brazil and its neighboring countries including Argentina, Costa Rica, Venezuela; and also includes Andrade and Serra Azul captive iron ore mines. The Europe segment includes Flat and Long operations, and through October 30, 2025, included Bosnia and Herzegovina captive iron ore mines; Sustainable Solutions division includes Downstream Solutions and Tubular operations of the European business and our renewables operations in India. The Others segment includes the Flat, Long and Tubular operations of Ukraine and South Africa, the captive iron ore mines in Ukraine, holding companies and intragroup stock margin eliminations. Mining segment includes iron ore operations of ArcelorMittal Mines Canada and ArcelorMittal Liberia.

Own iron ore production: includes total of all finished production of fines, concentrate, pellets and lumps and includes share of production.

Price-cost effect: a lack of correlation or a lag in the corollary relationship between raw material and steel prices, which can either have a positive (i.e. increased spread between steel prices and raw material costs) or negative effect (i.e. a squeeze or decreased spread between steel prices and raw material costs).

Return on capital employed (ROCE): refers to operating income, excluding impairment and special items, plus income from associates, JVs and other investments (excluding impairments and special items, if any), minus income taxes (excluding one-off tax charges) divided by the average equity plus net debt for the period.

Shipments: information at segment and Group level eliminates intra-segment shipments (which are primarily between Flat/Long plants and Tubular plants) and inter-segment shipments respectively. Shipments of Downstream Solutions are excluded.

Working capital change (working capital investment / release): refers to movement of change in working capital - trade accounts receivable plus inventories less trade and other accounts payable.

Forward-Looking Statements

This document contains forward-looking information and statements about ArcelorMittal and its subsidiaries. These statements include financial projections and estimates and their underlying assumptions, statements regarding plans, objectives and expectations with respect to future operations, products and services, and statements regarding future performance. Forward-looking statements may be identified by the words “believe”, “expect”, “anticipate”, “target”, "projected", "potential", "intend" or similar expressions. Although ArcelorMittal’s management believes that the expectations reflected in such forward-looking statements are reasonable, investors and holders of ArcelorMittal’s securities are cautioned that forward-looking information and statements are subject to numerous risks and uncertainties, many of which are difficult to predict and generally beyond the control of ArcelorMittal, that could cause actual results and developments to differ materially and adversely from those expressed in, or implied or projected by, the forward-looking information and statements. These risks and uncertainties include those discussed or identified in the filings with the Luxembourg Stock Market Authority for the Financial Markets (Commission de Surveillance du Secteur Financier) and the United States Securities and Exchange Commission (the “SEC”) made or to be made by ArcelorMittal, including ArcelorMittal’s latest Annual Report on Form 20-F on file with the SEC. ArcelorMittal undertakes no obligation to publicly update its forward-looking statements, whether as a result of new information, future events, or otherwise.

Non-GAAP/Alternative Performance Measures

This press release includes certain non-GAAP financial/alternative performance measures. ArcelorMittal presents net debt and change in working capital as additional measures to enhance the understanding of its financial position, changes to its capital structure and its credit assessment and to provide additional information to investors and management with respect to the Company’s cash flows. Non-GAAP financial/alternative performance measures should be read in conjunction with, and not as an alternative to, ArcelorMittal's financial information prepared in accordance with IFRS. Comparable IFRS measures and reconciliations of non-GAAP financial/alternative performance measures are presented herein.