The Chacatos were a Native American people who lived in the upper Apalachicola River and Chipola River basins in what is now Florida in the 17th century. The Spanish established two missions in Chacato villages in 1674. As a result of attempts by the missionaries to impose full observance of Christian rites and morals on the newly converted Chacatos, many of them rebelled, trying to murder one of the missionaries. Many of the rebels fled to Tawasa, while others joined the Chiscas, who had become openly hostile to the Spanish. Other Chacatos moved to missions in or closer to Apalachee Province, abandoning their villages west of the Apalachicola River.

In the late 17th century, one village of Chacatos moved from the center of Apalachee Province to near where the Chattahoochee and Flint rivers join to form the Apalachicola River, close to a Sabacola village and mission. That village was abandoned after it was attacked by Apalachicolas and others. Other Chacatos lived in small settlements scattered across the Florida panhandle, and in Tawasa and Tiquepache villages in Alabama.

After the destruction of the Apalachee Province missions by the English of the Province of Carolina and their Native American allies in 1704, the surviving Chacatos moved west with Apalachees and other peoples of the province, settling in the vicinity of Pensacola and Mobile bays. Some of those Chacatos may have been absorbed into the Choctaw nation. When West Florida was transferred to Great Britain in 1763, other Chacatos moved west to Louisiana.

In the 17th and earliest 18th centuries, when they lived in the eastern panhandle of Florida, the Spanish usually called the people "Chacato", and less often, "Chacta", "Chacto", "Chata", and "Chato". "Chatot" is the name commonly used in English sources through most of the 20th century, although scholars have recently used "Chacato". After they moved west to the area around Mobile Bay, and later to west of the Mississippi River in Louisiana, they were often also called "Chactoo", "Chacchou", "Chaetoo" and "Chattoo". Other forms of the name have included "Chacâto", "Chaqto", and "Chactot". Galloway notes that chato is Spanish for "flat" or "roman-nosed", and speculates that the Spanish called the people that because they practiced artificial cranial deformation.

Milanich notes that confusion of the names "Chatot" and "Chactato" with the Choctaw of Mississippi may have been responsible for the name of Choctawhatchee Bay. Galloway says that the Chacatos and Choctaws should not be confused, that the names are phonetically distinct, and were consistently used to refer to distinct peoples in the 18th century. Swanton states that the Choctawhatchee River in Florida and Bayou Chattique, Choctaw Point, and Choctaw Swamp near Mobile are probably named after the Chacato.

The Chacato spoke a Muskogean language, which may have been the same as that of several other peoples in western Florida, including the Amacano, Chine, Pacara, and Pensacola peoples. Swanton states that the language of the Chacato is "undoubtedly" a member of the southern division of the Muskogean stock. While it has been suggested that the Chacato were part of the Apalachee people, Hann notes that the Spanish used interpreters to translate from Chacato to Apalachee, and other interpreters to translate from Apalachee to Spanish. Martin states that suggestions that the Chacato language is related to Choctaw are unreliable.

The Chacato may have lived along one or more rivers flowing into Choctawhatchee Bay. A map in Martin shows the Chacato occupying an area along the Gulf Coast of Florida between the Apalachicola and Choctawhatchee rivers. At the time of first contact with the Spanish, the people they called Chacato lived in the upper part of the Chipola River basin and the adjacent section of the Appalachicola River in the area of the Fort Walton culture, primarily in what is now Jackson County, Florida. A number of archaeological sites in the area, including the Waddells Mill Pond Site, a fortified village site with two mounds, may have been occupied by the ancestors of the historic Chacato. Pottery found in the historic Chacato settlement area is more closely related to that of Apalachee Province than to that of the peoples of the Pensacola and Mobile bays. The subsistence economy of the Chacatos also resembled that of the Apalachees, rather than the peoples to their west.

The Chacatos appear to be an exception to their neighbors in that inheritance of the chieftainship did not necessarily pass to the offspring of the previous chief's eldest sister. The Chacato, along with the Apalachees and Muscogees, applied the title usinulo (beloved son) to one of the chief's sons. The Chacatos also shared use of the leadership titles inija (second-in-command) and chacal (assistant to an inija) with the Apalachee and the Timucua peoples.