Fox (known by a variety of different names, including Mesquakie (Meskwaki), Mesquakie-Sauk, Mesquakie-Sauk-Kickapoo, Sauk-Fox, and Sac and Fox) is an Algonquian language, spoken by a thousand Meskwaki, Sauk, and Kickapoo in various locations in the Midwestern United States and in northern Mexico.

The tribal school at the Meskwaki Settlement in Iowa incorporates bilingual education for children.

"[8] Prominent scholars doing research on the language include Ives Goddard[9] and Lucy Thomason of the Smithsonian Institution and Amy Dahlstrom of the University of Chicago.

Until the early 1900s, Fox was a phonologically very conservative language and preserved many features of Proto-Algonquian; records from the decades immediately following 1900 are particularly useful to Algonquianists for this reason.

[12] "Fox I" is an abugida based on the cursive French alphabet (see Great Lakes Algonquian syllabics).