The 2020 census found 13,216 people in the township.

Located in the southeastern part of the county, it borders the following townships: A large part of the county seat of Defiance is located in northern Defiance Township.

[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.

U.S. Route 24 travels from east to west through the northwestern corner of Defiance Township.