Located in the southwestern corner of the county, it borders the following townships and city: Part of the city of Reynoldsburg occupies the western end of Etna Township, part of the village of Kirkersville occupies the eastern end, and the unincorporated community of Etna lies in the central part of the township.

[6] Two Native American mounds, known as the "Etna Township Mounds", are located within the township.

[7] Etna Township is located entirely within the Refugee Tract.

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,[8] 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.