Located in the southern part of the county along the Ohio River, it borders the following townships: Across the Ohio River lies Kentucky to the south: Greenup County to the southeast, and Lewis County to the southwest.

No municipalities are located in Washington Township, although the census-designated place of West Portsmouth lies in the northern part of the township.

[4] 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.

Citizens of the township are served by the Washington-Nile Local School District.