Exhibit 15.9 CONSENT OF QUALIFIED PERSON Re: Annual Report on Form 20-F of ArcelorMittal I, Michael Spleit, an employee of ArcelorMittal, in connection with ArcelorMittal’s Annual Report on Form 20-F for the year ended December 31, 2021 (the “2021 20-F”): a) certify that I have supervised and validated the preparation of the ArcelorMittal Liberia Phase 2 and Phase 3 mineral reserve estimates; b) consent to the use of and references to my name, including my status as an expert or “qualified person” (as defined in Subpart 1300 of Regulation S-K promulgated by the U.S. Securities and Exchange Commission), in connection with the 2021 20-F and the ArcelorMittal Liberia Phase 2 and Phase 3 mineral reserve estimates; and c) consent to the incorporation by reference of the 2021 20-F into the Registration Statements Nos. 333-147382, 333-153576, 333-162697 and 333-170117 on Form S-8 and Registration Statement No. 333-256031 on Form F-3 (and any amendments or supplements thereto). I, Michael Spleit, am responsible for authoring, and this consent pertains to ArcelorMittal Liberia Phase 2 and 3 mineral reserves. I, Michael Spleit, certify that I have read the 2021 20-F and that it fairly and accurately represents the mineral reserves for ArcelorMittal Liberia. Dated: 2022-03-07 /s/Michael Spleit Michael Spleit, ing. Mining Technical Services Manager, ArcelorMittal Mining Ltd. ArcelorMittal Limited T +44(0)20 7543 1130 7th Floor F +44 (0)20 7543 1165 Berkeley Square House www.arcelormittal.com Berkeley Square London W1J 6DA Registered office details United Kingdom Registred no. 03335595

CONSENT OF QUALIFIED PERSON Re: Annual Report on Form 20-F of ArcelorMittal I, Dr. Alistair Bryan Jeffcoate an employee of ArcelorMittal, in connection with ArcelorMittal's Annual Report on Form 20-F for the year ended December 31, 2021 (the "2021 20-F"): a) certify that I have supervised and validated the preparation of the ArcelorMittal Liberia mineral resource estimates for the Mt. Tokadeh, Mt. Gangra and Mt Yuelliton deposits; b) consent to the use of and references to my name, including my status as an expert or "qualified person" (as defined in Subpart 1300 of Regulation S-K promulgated by the U.S. Securities and Exchange Commission), in connection with the 2021 20-F and ArcelorMittal Liberia mineral resource estimates for the Mt. Tokadeh, Mt. Gangra and Mt Yuelliton deposits; and c) consent to the incorporation by reference of the 2021 20-F into the Registration Statements Nos. 333-147382, 333-153576, 333-162697 and 333-170117 on Form S-8 and Registration Statement No. 333-256031 on Form F-3 (and any amendments or supplements thereto). I am responsible for authoring, and this consent pertains to, ArcelorMittal Liberia mineral resource estimates for the Mt. Tokadeh, Mt. Gangra and Mt Yuelliton deposits. I certify that I have read the 2021 20-F and that it fairly and accurately represents the mineral resources for each property for which I am responsible. Dated: 25th February 2022 /s/Dr. Alistair Bryan Jeffcoate Dr. Alistair Bryan Jeffcoate MAusIMM (CP) ArcelorMittal Limited T +44(0)20 7543 1130 7th Floor F +44 (0)20 7543 1165 Berkeley Square House www.arcelormittal.com Berkeley Square London W1J 6DA Registered office details United Kingdom Registred no. 03335595