According to the United States Census Bureau, the township has a total area of 35.3 square miles (91.4 km2), all land.

Main highways include: Organization of Westside Township was approved by the Nobles County Board on February 6, 1877.

Westside Township is located in Minnesota's 1st congressional district, represented by Mankato educator Tim Walz, a Democrat.

At the state level, Westside Township is located in Senate District 22, represented by Republican Doug Magnus, and in House District 22A, represented by Republican Joe Schomacker.

Westside Township is represented by Nobles County Commissioner Gene Metz.