The 2020 census found 9,399 people in the unincorporated parts of the township, outside the city of Lima.

[4] Bath Township was the first permanent settlement within the present day bounds of Allen County.

There is no record of its settling in the 1831 registers of the newly formed Allen County, yet it was a fully functioning community by that time.

Until the formation of Lima and the nearby Ottawa, the future land was also part of Bath.

[6][7] 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.