A family of languages in North America. They consist mainly of the Athabaskan (or Athapaskan) languages far in the north-west, around Alaska, British Columbia, and Yukon. The family also includes Navaho and Apache, which moved into the southern United States in comparatively recent times. Some of the better-known Athapaskan peoples of Canada are the Chippewyan, Slave (pronounced Slavey), Beaver, Dogrib, and Gwich'in.

The Navaho (Navajo) and Apache moved south from Canada about a thousand years ago. Some time before that another Na-Dene branch moved into Washington state, but all of these are now extinct or close to it.

The Tlingit language of British Columbia is believed to be a more distant branch of Na-Dene. Haida might also be. Linguists who exclude these call the main family Eyak-Athabaskan (Eyak-Athapaskan), Eyak being an Alaskan language more divergent from the rest but definitely related. The theory that Athabaskan, Tlingit, and Haida could be related was put forward by Edward Sapir and later endorsed by Joseph Greenberg in his controversial classification.

No wider affinities with other American languages can be detected. Indeed, some people believe the Na-Dene entered North America over Beringia at a later date than the main Clovis population, and that their language family has affinity with others in Eurasia: specifically a few linguists have suggested a relationship to the huge Sino-Tibetan family including Chinese, and some holdouts in mountain fastnesses such as the Caucasus. This hypothetical super-family, whose existence is not widely accepted, is called Dene-Caucasian.

Typical of the languages is to have voiceless unaspirated and aspirated stops, but not voiced. The symbols such as b d g represent the unaspirated, and p t k the aspirated, in the most common transcriptions: hence the variation Atha{b/p}askan. They typically have lateral fricatives and affricates, voiced and voiceless.

The verb is notoriously and bafflingly complex.