The Atakapan people ( /əˈtɑːkəpə/) are a Southeastern culture of Native American tribes who spoke Atakapa and historically lived along the Gulf of Mexico. They called themselves the Ishak, pronounced "ee-SHAK", which translates as "The People". Although the people were decimated by infectious disease after European contact, descendants still live in Louisiana and Texas. In 2006 the Atakapa-Ishak met as one people.

Their name was also spelled Attakapa, Attakapas, or Attacapa. Choctaw in origin, it means "man eater", and was the name learned by the Europeans from the Choctaw. The peoples lived in river valleys, along lake shores, and coasts from Galveston Bay, Texas to Vermilion Bay, Louisiana.

After 1762, when Louisiana was transferred to Spain, little was written about the Atakapan. Infectious disease epidemics of the late 18th century caused many fatalities among them. Survivors joined the Caddo, Koasati, and other surrounding tribes, although some culturally distinct Atakapan people survived into the 20th century.