The Arapahoan languages are a subgroup of the Plains group of Algonquian languages: Nawathinehena, Arapaho, and Gros Ventre.
Nawathinehena is extinct and Arapaho and Gros Ventre are both endangered.
Besawunena, attested only from a word list collected by Kroeber, differs only slightly from Arapaho, but a few of its sound changes resemble those seen in Gros Ventre. It had speakers among the Northern Arapaho as recently as the late 1920s.
Nawathinehena, is also attested only from a word list collected by Kroeber, and was the most divergent language of the group.
Another reported Arapahoan variety is the extinct Ha'anahawunena, but there is no documentation of it.