Dené–Yeniseian languages in the context of "Na-Dene languages"

The Yeniseian languages (/ˌjɛnɪˈseɪən/ YEN-ih-SAY-ən; sometimes known as Yeniseic, Yeniseyan, or Yenisei-Ostyak; occasionally spelled with -ss-) are a family of languages that are spoken by the Yeniseian people in the Yenisei River region of central Siberia. As part of the proposed Dene–Yeniseian language family, the Yeniseian languages have been argued to be part of "the first demonstration of a genealogical link between Old World and New World language families that meets the standards of traditional comparative-historical linguistics". The only surviving language of the group today is Ket.

From hydronymic and genetic data, it is suggested that the Yeniseian languages were spoken in a much greater area in ancient times, including parts of northern China and Mongolia. It has been further proposed that the recorded distribution of Yeniseian languages from the 17th century onward represents a relatively recent northward migration, and that the Yeniseian urheimat lies to the south of Lake Baikal.

Na-Dene (/ˌnɑːdɪˈneɪ/ NAH-dih-NAY; also Nadene, Na-Dené, Athabaskan–Eyak–Tlingit, Tlina–Dene) is a family of Native American languages that includes at least the Athabaskan languages, Eyak, and Tlingit languages. Haida was formerly included but is now generally considered a language isolate. By far the most widely spoken Na-Dene language today is Navajo, also the most spoken indigenous language north of Mexico.

Some linguists have proposed that the Na-Dene family is related to the Yeniseian languages of central Siberia, creating a Dene–Yeniseian family. However, this proposal has not been accepted by some linguists.