The 5th Senate district of Wisconsin is one of 33 districts in the Wisconsin Senate. Located in southeast Wisconsin, the district is composed of parts of western Milwaukee County, and eastern Waukesha County. It includes the cities of Brookfield and Pewaukee, and the villages of Elm Grove and Pewaukee, as well as most of the cities of Wauwatosa and West Allis, and parts of the cities of Milwaukee and Waukesha.

The Wisconsin Senate is the upper house of the Wisconsin State Legislature. Together with the larger Wisconsin State Assembly they constitute the legislative branch of the state of Wisconsin. The powers of the Wisconsin Senate are modeled after those of the U.S. Senate.