According to the 2021 census gazetteer files, Pigeon Grove Township has a total area of 35.86 square miles (92.88 km2), all land.

[2] As of the 2020 census[1] there were 1,103 people, 512 households, and 325 families residing in the township.

There were 556 housing units at an average density of 15.50 per square mile (5.98/km2).

The racial makeup of the township was 97.10% White, 0.18% African American, 0.00% Native American, 0.18% Asian, 0.09% Pacific Islander, 0.54% from other races, and 1.90% from two or more races.

34.80% of all households were made up of individuals, and 22.30% had someone living alone who was 65 years of age or older.