Dakota (also Dakhota) is a Siouan language spoken by the Dakota people of the Sioux tribes. Dakota is closely related to and mutually intelligible with the Lakota language.

Dakota has two major dialects with two sub-dialects each (and minor variants, too):

The two dialects differ phonologically, grammatically, and to a large extent, also lexically. They are mutually intelligible to a high extent, although Western Dakota is lexically closer to the Lakota language with which it has higher mutual intelligibility.

For a comparative table of the various writing systems conceived over time for the Sioux languages, cf. the specific section of the article Sioux language.

Dakota has five oral vowels, /a e i o u/, and three nasal vowels, /aŋ iŋ uŋ/.

In respect to phonology Eastern and Western Dakota differ particularly in consonant clusters. The table below gives the possible consonant clusters and shows the differences between the dialects:

The two dialects also differ in the diminutive suffix (-da in Santee, and -na in Yankton-Yanktonai and in Sisseton) and in a number of other phonetic issues that are harder to categorize. The following table gives examples of words that differ in their phonology.