Their name is an abbreviation of kadohadacho (one of the tribes of the Caddo), meaning the "true chiefs." The Caddo called themselves hasinai, "our own culture."

The Caddo is one of a confederacy of tribes of North American Indians that composed the Caddoan linguistic family. The Caddo proper originally occupied the lower Red River area in what are now Louisiana, southwest Arkansas, and northeast Texas.

Member tribes included: Arikara, Wichita, Pawnee. These were farmers who also hunted buffalo.

In the late 17th century they numbered 8,000 persons living in villages scattered along the Red River and its tributaries. This is also the region of the Caddoan archaeological complex, where many striking examples of Indian workmanship have been found. Archaeological research shows the Caddoan tenancy to be ancient.

In 1541, the Caddo opposed explorer DeSoto, who recognized their bravery, and in 1687, they encountered the survivors of LaSalle's epedition. Lemoyne d'Iberville rallied them to the side of the French at the beginning of the 1700s. The Caddo first opposed the Choctaw, then allied themselves with the Choctaw against the Osage at the end of the 18th century.

When Louisiana was purchased by the U.S., white immigration increased, and the tribe was pushed farther south. Under the treaty of 1835 the Caddo ceded all their land to the U.S. and settled in Texas. There they lived peaceably for a time, but in 1859 threats of a massacre by the whites forced them to flee to east central Oklahoma, where they were settled on a reservation on the banks of the Washita River. During the Civil War they remained loyal to the Union. They were moved to Kansas and finally settled on a reservation in Oklahoma with the Wichita in 1902.

When first encountered, the Caddo were a semi-sedentary agricultural people. They lived in conical-shaped dwellings constructed of poles covered with a thatch of grass; these were grouped around ceremonial centres of temple mounds. Skillful at pottery and basket making, they wove cloth of vegetable fibres and, on special occasions, wore mantles decorated with feathers. They also wore nose rings and practiced tattooing. Descent was matrilineal, and a hereditary upper group, marked by head deformation and other status symbols, directed political and religious activities. There are scattered reports of ceremonial human sacrifice and cannibalism. These and other traits relate the Caddo to the centres of high Indian culture in Mexico and Yucatán.