The 2020 census reported 18,050 people living in the township.

The Mad River, a southwest-flowing tributary of the Great Miami River, forms the southeast border of the township.

Several populated places are located in Bethel Township: Statewide, other Bethel Townships are located in Miami and Monroe counties.

[4] 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.

The board is composed of Chris Crowley (Chairman), Alec R. Ashbaugh, and Nancy Brown.