Muskogean (/məˈskoʊɡiən/ mə-SKOH-ghee-ən; also Muskhogean) is a language family spoken in the Southeastern United States. Members of the family are Indigenous languages of the Americas. Typologically, Muskogean languages are highly synthetic and agglutinative. One documented language, Apalachee, is no longer spoken, and the remaining languages are critically endangered.

The Muskogean family consists of Alabama, Chickasaw, Choctaw, Muscogee (or Creek), Koasati, Apalachee, and Hitchiti-Mikasuki. Hitchiti is generally considered a dialect of Mikasuki. "Seminole" is sometimes used for a dialect of Muscogee spoken in Oklahoma.

The major subdivisions of the family have long been controversial, but the following lower-level groups are universally accepted: Choctaw–Chickasaw, Alabama–Koasati, Hitchiti–Mikasuki, and Muscogee. Apalachee is no longer spoken; its precise relationship to the other languages is uncertain, but Mary Haas and Pamela Munro both classify it with the Alabama–Koasati group.

For connections among these groupings, one influential classification is that of Mary Haas and Karen Booker, in which "Western Muskogean" (Choctaw-Chickasaw) is seen as one major branch, and "Eastern Muskogean" (Alabama-Koasati, Hitchiti-Mikasuki, and Muscogee) as another. Within Eastern Muskogean, Alabama-Koasati and Hitchiti-Mikasuki are generally thought to be more closely related to each other than to Muscogee. That classification is reflected in the list below:

A different classification has been proposed by Pamela Munro. In her classification, the languages are divided into a "Southern Muskogean" branch (Choctaw-Chickasaw, Alabama-Koasati, and Hitchiti-Mikasuki) and a "Northern Muskogean" one (Muscogee). Southern Muskogean is then subdivided into Hitchiti-Mikasuki and a "Southwestern Muskogean" branch containing Alabama-Koasati and "Western Muskogean" (Choctaw-Chickasaw). The classification is reflected in the list below:

Several sparsely attested languages have been claimed to be Muskogean languages. George Broadwell suggested that the languages of the Yamasee and Guale were Muskogean. However, William Sturtevant argued that the "Yamasee" and "Guale" data were Muscogee and that the language(s) spoken by the Yamasee and Guale people remain unknown. It is possible that the Yamasee were an amalgamation of several different ethnic groups and did not speak a single language. Chester B. DePratter describes the Yamasee as consisting mainly of speakers of Hitchiti and Guale. The historian Steven Oatis also describes the Yamasee as an ethnically mixed group that included people from Muskogean-speaking regions, such as the early colonial-era native towns of Hitchiti, Coweta, and Cussita.

The Amacano, Chacato, Chine, Pacara, and Pensacola people, who lived along the Gulf Coast of Florida from the Big Bend Coast to Pensacola Bay, are reported to have spoken the same Muskogean language, which may have been closely related to Choctaw.

Sparse evidence indicates that a Muskogean language was spoken by at least some of the people of the paramount chiefdom of Cofitachequi in northeastern South Carolina. If so, that would be the most eastern outpost of Muskogean. The people of Cofitichequi were probably absorbed by nearby Siouan and Iroquoian speakers in the late 17th century.