The Chitimacha (also Chitimachan, Chetimacha) are a Native American federally recognized tribe that lives in the U.S. state of Louisiana, mainly in St. Mary Parish. They currently number about 720 people. The Chitimacha language is a language isolate.

The Chitimacha's historic home was the southern Louisiana coast. They and their ancestors lived there for about 2,500 years and perhaps as long as 6,000. They had migrated from the area surrounding modern Natchez, Mississippi, and before that, from eastern Texas.

In the early 18th century, the Chitimacha encountered French colonists, who raided their territory in search of slaves. By the time peace was reached in 1718, the population had declined drastically, through exposure to new infectious diseases to which they had no immunity and warfare. Survivors were forced to move north.

One hundred years later, the arrival of Acadian refugees in their area brought a further decline in the Chitimacha population.

Some members married Acadians and became acculturated to their community, including converting to Catholicism. New settlers grabbed land. In 1917, the tribal leadership sold what was left of the Chitimacha land to the United States government. By 1930, the Chitimacha population had dropped to just 51 people.