Union Township is one of the twelve townships of Miami County, Ohio, United States.

The 2020 census found 9,569 people in the township.

Located in the southwestern corner of the county, it borders the following townships: Several populated places are located in Union Township: It is one of twenty-seven Union Townships statewide.

[4] 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.