[4] According to the United States Census Bureau, the township has a total area of 36.1 square miles (93.4 km2), all land.

21.4% of all households were made up of individuals, and 7.1% had someone living alone who was 65 years of age or older.

About 9.1% of families and 10.8% of the population were below the poverty line, including 15.4% of those under the age of eighteen and 9.8% of those 65 or over.

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

At the state level, Selma Township is located in Senate District 22, represented by Republican Doug Magnus, and in House District 22B, represented by Republican Rod Hamilton.