Mangum is a city in Greer County, Oklahoma, United States. The population was 3,010 at the 2010 census. It is the county seat of Greer County.
Mangum is home to the fourth longest-lasting light bulb, located in a fire house, according to The Guinness Book of World Records.
Mangum is located at 34°52′41″N 99°30′19″W / 34.87806°N 99.50528°W / 34.87806; -99.50528 (34.878090, -99.505217).