In the 1980 Cook County State's Attorney election, incumbent second-term state's attorney Bernard Carey, a Republican, was unseated by Democrat Richard M. Daley.

The Cook County State's Attorney functions as the state of Illinois's district attorney for Cook County, Illinois, and heads the second-largest prosecutor's office in the United States. The office has over 700 attorneys and 1,100 employees. In addition to direct criminal prosecution, the state's attorney's office files legal actions to enforce child support orders, protect consumers and the elderly from exploitation, and assist thousands of victims of domestic violence every year.