As of the census[1] of 2000, there were 401 people, 146 households, and 110 families residing in the township.

The racial makeup of the township was 99.50% White, 0.25% Asian, 0.25% from other races.

21.2% of all households were made up of individuals, and 7.5% had someone living alone who was 65 years of age or older.

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

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