1915 Chicago mayoral election

In the Chicago mayoral election of 1915, Republican William Hale Thompson defeated Democrat Robert Sweitzer.

Five-term incumbent Democrat Carter Harrison Jr. was defeated in the Democratic primary by Cook County Clerk Sweitzer. In the Republican primary, Thompson defeated Harry Olson by a 1.33% margin. Thompson was a former Cook County commissioner and former Chicago alderman, while Olson was the incumbent chief justice of the Municipal Court of Chicago.

This was the first mayoral election to take place in Chicago after Illinois granted partial women's suffrage, enabling women to vote in Chicago mayoral elections among other elections. The election was held on April 6.