U.S. Route 81 (US-81) is a north–south U.S. highway running through the central United States' Great Plains region, from Fort Worth, Texas to the U.S.–Canadian border at Pembina, North Dakota. A 229.28-mile (368.99 km) segment of the highway lies within the state of Oklahoma. US-81 crosses the Red River from Texas south of Terral, passing through several Oklahoma cities, such as Chickasha, El Reno, Kingfisher, and Enid, before entering Kansas north of Renfrow.

Kingfisher is a city in and the county seat of Kingfisher County, Oklahoma,. The population was 4,903 at the time of the 2020 census. It is the former home and namesake of Kingfisher College. According to the Encyclopedia of Oklahoma History and Culture, Kingfisher is now primarily a bedroom community for people employed in Enid and Oklahoma City.