Wayne Township, one of eleven in Warren County, Ohio, is located in the northeast part of the county and includes the village of Waynesville, Ohio. Its population in 2000 was 7,250, up from 5,744 in 1990.

One of the original townships of Warren County, it was created on May 10, 1803, nine days after the county was erected, and named for General "Mad" Anthony Wayne. It is bounded on the south by Turtlecreek Township and Washington Township; on the east by Massie Township and the Clinton County township of Chester; on the north by the Greene County township of Spring Valley and the Montgomery County township of Washington; and on the west by Clearcreek Township.

The original boundaries were: "Beginning at the northewat corner of Section 33 in the third township; thence east to the northeast corner of the county; thence south to a point drawn due east from the north boundard of the third military range; thence due west to the southwest corner of Section 25, in the fourth range; thence due north to the place of beginning." When created, Warren County extended much farther to the east than today and Wayne Township encompassed a large area now in Clinton County. On June 26, 1806, Eaton Township was created from that part of Wayne lying east of Caesars Creek. On August 4, 1804, a strip two miles wide was taken from the south side and made part of the new Turtlecreek Township and on September 11, 1815, a two-mile wide strip was cut of the west side and added to the new Clearcreek Township. On October 10, 1850, Massie Township was created from parts of Wayne and Washington Townships.

The village of Corwin is in the township, as are the communities of Mount Holly and Crosswick. The Little Miami River, which forms a portion of the township's boundary, flows through the middle of the township. The Little Miami Bike Trail, along the route of the former Little Miami Railroad, also passes through the township.

The portion of Wayne Township east of the Little Miami is in the Virginia Military District and was surveyed with the metes and bounds system, while the area west of the Little Miami was surveyed on the same plan as used in the Symmes Purchase.

Most of the township is in the Wayne Local School District, but parts are in the Lebanon, Spring Valley, Clinton Massie and Xenia districts.

The township is mainly in the Waynesville telephone exchange, but parts are in the Spring Valley, Bellbrook, Lebanon, and Centerville exchanges.