Located in the southern part of the county, it borders the following townships: Part of the village of Oak Hill is located in eastern Jefferson Township.

[4] It is one of twenty-four Jefferson Townships statewide.

[5] Jefferson Township has the twelfth largest population of people of Welsh descent in the United States, and sixth largest in Ohio.

[6] 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,[7] 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.