The present name, adopted in 1879, is for Milo D. Mason, an early settler.

14.8% of all households were made up of individuals, and 5.2% had someone living alone who was 65 years of age or older.

About 7.0% of families and 7.6% of the population were below the poverty line, including 6.2% of those under the age of eighteen and none of those 65 or over.

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

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