Duncan is located in southern Oklahoma in Stephens County (of which it is the county seat) about 25 miles east of Lawton/Ft. Sill along U.S. Highway 81.

Local attractions include the "On the Chisholm Trial" statue and Museum, giving visitors a feel for life on the storied trail, and the Stephens County Historical Museum, covering a more general approach to county history.

Outdoor recreational opportunities include Clear Creek Lake and Lake Fuqua to the east are both well-known by locals for their excellent fishing. In addition, Lake Humphreys and Duncan Lake are smaller but can produce nice fish.