ECAC Hockey is one of the five NCAA Men's Division I Ice Hockey conferences that compete in NCAA Division I ice hockey. The conference used to be affiliated with the Eastern College Athletic Conference, a consortium of over 300 colleges in the eastern United States. This relationship ended in 2004; however the ECAC abbreviation was retained in the name of the hockey conference. ECAC Hockey also operates a women's ice hockey conference, with the same members as the men's conference.

ECAC Hockey was founded in 1962. In June 1983, concerns that the Ivy League schools were potentially leaving the conference and disagreements over schedule length versus academics caused Boston University, Boston College, Providence, Northeastern and New Hampshire to decide to leave the ECAC to form what would become Hockey East, which began play in the 1984–85 season. By that fall, Maine also departed the ECAC for the new conference. This left the ECAC with twelve teams (Army, Brown, Clarkson, Colgate, Cornell, Dartmouth, Harvard, Princeton, RPI, St. Lawrence, Vermont, and Yale). Army would stay in the conference until the end of the 1990–91 season, at which point they became independent (they now play in Atlantic Hockey) and were replaced by Union College. Vermont left the ECAC for Hockey East at the end of the 2004–05 season, and were replaced in the conference by Quinnipiac.