It is located in the west-central part of the county, midway between Hamilton and Oxford.

It is named for Hanover County, Virginia, where the early settlers originated.

[citation needed] The twelfth in order of creation, Hanover Township was established from Ross and St. Clair townships by the Butler County Commissioners on December 2, 1811.

Located in the center of the county, it borders the following townships: 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.

In the nineteenth century, the Cincinnati, Hamilton, and Dayton Railroad's Richmond division crossed the township en route from Hamilton with a station at McGonigle.