Debuts
- February: WQAM is launched in Miami, Florida by the W.W. Luce of the Electrical Equipment Company.
- 26 July: Experimental station 8ACS (later WHK) is launched in Cleveland, Ohio, by Warren C. Cox/Cox Mfg. Co.
- 19 September: The first commercially-licensed radio broadcasting station in the United States, WBZ, is launched by the Westinghouse Electric Corporation in Springfield, Massachusetts.
- 1 October: WJZ is launched by Westinghouse in Newark, New Jersey.
- 11 November: KYW is launched by Westinghouse in Chicago.
Read more about this topic: 1921 In Radio