[3] Located in the southeastern corner of the county, it borders the following townships: No municipalities are located in Williamsfield Township, although the unincorporated community of Williamsfield lies in the township's center.

Named for an early landowner,[4] it is the only Williamsfield Township statewide.

[5] When whites first arrived in what is now Williamsfield Township, the land was inhabited by a small number of Delaware Indians.

The first white man to settle in the township was Charles Case, who came from Connecticut in 1804.

[6] 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.