The 2020 census reported 2,112 people living in the township.

Located in the southeastern part of the county, it borders the following townships: The village of Mutual is located in the center of the township.

Union Township was established about 1805, but since the records were lost the exact date is likely unknown.

Believed to be a work of the Adena culture, the mound is an archaeological site and is listed on the National Register of Historic Places.

[6] 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.