Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the registration statements (No. 333-228907 and No. 333-222170) on Form S-8 of our reports dated February 16, 2022, with respect to the consolidated financial statements of Altice USA, Inc. and the effectiveness of internal control over financial reporting.

/s/ KPMG LLP

New York, New York

February 16, 2022