Bay Township is one of the twelve townships of Ottawa County, Ohio, United States.

The 2020 census found 1,142 people in the township.

Located in the southern part of the county along Sandusky Bay, it borders the following townships: A small part of the city of Port Clinton, the county seat of Ottawa County, is located in the northeastern corner of Bay Township.

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,[4] 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.