Canadian County is a county located in the U.S. state of Oklahoma. As of the 2020 census, the population was 154,405, making it the fourth most populous county in Oklahoma. Its county seat is El Reno.

El Reno is a city in and county seat of Canadian County, Oklahoma, United States. As of the 2020 census, the city population was 16,989, marking a change of 1.55% from 16,729, recorded in the 2010 census. The city was begun shortly after the 1889 land rush and named for the nearby Fort Reno. It is located in Central Oklahoma, about 25 miles (40 km) west of downtown Oklahoma City.