According to the 2021 census gazetteer files, Lone Grove Township has a total area of 36.86 square miles (95.47 km2), all land.

[2] (This list is based on USGS data and may include former settlements.)

As of the 2020 census[1] there were 632 people, 279 households, and 195 families residing in the township.

There were 262 housing units at an average density of 7.11 per square mile (2.75/km2).

22.90% of all households were made up of individuals, and 18.60% had someone living alone who was 65 years of age or older.