Located in the northern part of the county along the Michigan state line, it borders the following townships: No municipalities are located in Bridgewater Township.

The township lies within the Toledo Strip, a contested ribbon of land over which Ohio and Michigan came to blows in an 1835–36 confrontation known as the Toledo War.

[4] Bridgewater Township was established around 1839, and first elections were held in 1840.

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.