[3] According to the United States Census Bureau, the township has a total area of 35.8 square miles (93 km2), all land.

The racial makeup of the township was 96.51% White, 0.58% Pacific Islander, 2.91% from other races.

15.3% of all households were made up of individuals, and 11.9% had someone living alone who was 65 years of age or older.

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

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