Poteau is a city in Le Flore County, Oklahoma, United States. It is part of the Fort Smith, Arkansas-Oklahoma Metropolitan Statistical Area. The population was 7,939 at the 2000 census, ranking fifth in the Greater Fort Smith Area. It is the county seat of Le Flore County. It is the home of the World's Highest Hill, Cavanal Hill. Within the city is Twyman Park, named for former mayor William G. Twyman.