Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in this Registration Statement on Form F-3 of our reports dated February 24, 2015, relating to the consolidated financial statements of ArcelorMittal and subsidiaries (the “Company”) (which report expresses an unqualified opinion and includes an explanatory paragraph regarding the Company’s change in the composition of reportable segments, as described in Notes 1 and 27), and the effectiveness of the Company’s internal control over financial reporting, appearing in the Annual Report on Form 20-F of the Company for the year ended December 31, 2014, and to the reference to us under the heading “Experts” in the Prospectus, which is part of this Registration Statement.

/s/ Deloitte Audit

Luxembourg, Grand Duchy of Luxembourg

March 2, 2015