It contains most of the city of Wauwatosa, along with the village of Elm Grove and much of northern Brookfield.

The district also contains landmarks such as the Medical College of Wisconsin, Froedtert Hospital, Mayfair Mall, and Webster Park.

[5] The 13th district was drawn somewhat in line with the western half of the previous Milwaukee County 18th district, though with some city of Milwaukee wards removed, and the village of Butler in Waukesha County added.

[6] The district has remained in the same vicinity since 1972, but the boundaries have moved further and further west.

The 2024 redistricting act moved the district back to the east, re-adding most of the city of Wauwatosa and shedding a large part of the city of Brookfield.