Arapaho is a town in Custer County, Oklahoma, United States. The population was 796 at the 2010 census. It is the county seat of Custer County. Its name derives from the Arapaho Indians.
Arapaho is located at 35°34′37″N 98°57′45″W / 35.57694°N 98.9625°W / 35.57694; -98.9625 (35.577014, -98.962370).
According to the United States Census Bureau, the town has a total area of 0.7 square miles (1.8 km²), all of it land.