The 2020 census found 53,477 people in the township.

Located in the north central part of the county, it borders the following townships and city: Several populated places are located in Plain Township: According to the United States Census Bureau, Plain Township has a total area of 28.5 square miles (73.81 km2), of which 28.3 square miles (73.29 km2) is land and 0.2 square mile (0.5 km2) is water.

[4] Statewide, other Plain Townships are located in Franklin, Wayne, and Wood counties.

The township is governed by a three-member board of trustees, who are elected in November of odd-numbered years to a four-year term beginning on the following January 1.

There is also an elected township fiscal officer,[5] who serves a four-year term beginning on April 1 of the year after the election, which is held in November of the year before the presidential election.