The Atakapa /əˈtɑːkəpə/ are an indigenous people of the Southeastern Woodlands, who spoke the Atakapa language and historically lived along the Gulf of Mexico. Europeans adopted this name from the competing Choctaw people, whom they first encountered. The Atakapan people, made up of several bands, called themselves the Ishak, pronounced "ee-SHAK", which translates as "The People." Within the tribe the Ishak identified as "The Sunrise People" and "The Sunset People". Although the people were decimated by infectious disease after European contact and declined as a tribe, survivors joined other tribes and their descendants still live in Louisiana and Texas. People identifying as Atakapa-Ishak had a gathering in 2006.

Their name was also spelled Attakapa, Attakapas, or Attacapa. It was the name by which the Choctaw people referred to them, meaning "man eater", for their practice of ritual cannibalism. Europeans encountered the Choctaw first during their exploration, and adopted their name for this people to the west. The peoples lived in river valleys, along lake shores, and coasts from Galveston Bay, Texas to Vermilion Bay, Louisiana.