The Big Ten Conference did not begin sponsoring women's basketball until the 1982-83 basketball season. In February 1982 during the 1981-82 season, the conference held a tournament at Michigan State in which Ohio State defeated Illinois 69-66 in the championship game. The conference has listed this in some publications as a regular season championship.
Championships by school
Bold indicates an outright championship.
References
List of Big Ten Conference women's basketball regular season champions Wikipedia(Text) CC BY-SA