Berne Township is one of the thirteen townships of Fairfield County, Ohio, United States.

Located in the southern part of the county, it borders the following townships: Two municipalities are located in Berne Township: part of the city of Lancaster, the county seat of Fairfield County, in the northwest; and the village of Sugar Grove in the south.

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.

Vacancies in the fiscal officership or on the board of trustees are filled by the remaining trustees.