Mustang, OK. Online Offers. Mustang is a growing suburban city in Canadian County, Oklahoma, United States and is part of the Oklahoma City Metropolitan Statistical Area. The population was 13,156 at the 2000 census. Mustang is a fast growing community, 15 miles southwest of downtown Oklahoma City. It is located in the southeast portion of Canadian County, one of the fastest growing counties in the state. Mustang is located at 35°23′34″N 97°43′22″W / 35.39278°N 97.72278°W / 35.39278; -97.72278 (35.392644, -97.722905).