The Cheyenne language (Tsėhesenėstsestotse or, in easier spelling, Tsisinstsistots) is a Native American language spoken by the Cheyenne people, predominantly in present-day Montana and Oklahoma in the United States. It is part of the Algonquian language family. Like all Algonquian languages, it has complex agglutinative morphology.

Cheyenne is one of the Algonquian languages, which is a subphylum of the Algic languages. Specifically, it is a Plains Algonquian language. However, Plains Algonquian, which also includes Arapaho and Blackfoot, is an areal rather than genetic subgrouping.

Cheyenne is spoken on the Northern Cheyenne Indian Reservation in Montana and in Oklahoma. It is spoken by about 1,000 people, all adults.

Cheyenne phonology is quite simple. While there are only three basic vowels, they can be pronounced in three ways: high pitch (e.g. á), low pitch (e.g. a), and voiceless (e.g. ė). The high and low pitches are phonemic, while vowel devoicing is governed by environmental rules, making voiceless vowels allophones of the voiced vowels. The phoneme /h/ is realized as [s] in the environment between /e/ and /t/ (h > s / e _ t). /h/ is realized as [ʃ] between [e] and [k] (h > ʃ / e _ k) i.e. /nahtóna/ nȧhtǒna alien, /nehtóna/ nėstǒna your daughter, /hehke/ heške his mother. The digraph ‘ts’ represents assibilated /t/; a phonological rule of Cheyenne is that underlying /t/ becomes affricated before an /e/ (t > ts/_e). Therefore, ‘ts’ is not a separate phoneme, but an allophone of /t/. The sound [x] is not a phoneme, but derives from other phonemes, including /ʃ/ (when /ʃ/ precedes or follows a non-front vowel, /a/ or /o/), and the past tense morpheme /h/ which is pronounced [x] when it precedes a morpheme which starts with /h/.