Located in the northern part of the county, it borders the following townships: No municipalities are located in Jefferson Township, although the unincorporated community of Clarktown lies in the township's southeast.

[5][6] Jefferson Township was established prior to 1810.

[6] In 1833, Jefferson Township contained two water power gristmills, one saw mill, and one horse mill and distillery, one tavern and one tan yard.

[7] 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.