Butler Township is one of the fourteen townships of Mercer County, Ohio, United States.

The 2020 census found 6,653 people in the township.

Located in the south central part of the county, it borders the following townships: The village of Coldwater is located in central Butler Township.

[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.