Gratis Township is one of the twelve townships of Preble County, Ohio, United States.

The 2020 census found 4,224 people in the township.

Located in the southeastern corner of the county, it borders the following townships: Two incorporated villages are located in Gratis Township: Gratis in the north, and West Elkton in the south.

[5] 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,[6] 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.