Paleosiberian (Palaeosiberian, Paleo-Siberian) languages or Paleoasian languages (from Greek palaios, "ancient") is a term of convenience used in linguistics to classify a disparate group of languages spoken in remote regions of Siberia. Their only common provenance is that they are held to have antedated the more dominant languages, particularly Tungus and latterly Turkic languages that have largely displaced them. Even more recently, Turkish (at least in Siberia) and especially Tungus, have been displaced in their turn by Russian. It is possible that the Merkits spoke a Paleosiberian language.

Five language isolates or at least very small language groups, not known to have any linguistic relationship to each other, compose the Paleo-Siberian languages:

1. Chukchi and its close relative, Koryak. Kamchadal is thought to be distantly related. Chukchi and Koryak are spoken in easternmost Siberia and are thriving. Kamchadal is spoken on the Kamchatka peninsula and is nearly extinct. The group as a whole is called Chukotko-Kamchatkan.

2. Yukaghir is spoken in two dialects: Odul in the lower Kolyma and Indigirka valleys and Chuvantsy, further inland and further east, now probably extinct. Yukaghir is held by some to be related to the Uralic languages.

3. Ket (or Yeniseian) is perhaps the last survivor of a small language family on the middle Yenisei and its tributaries. Attempts have been made to relate it to Sino-Tibetan and North Caucasian groups; more recently, it has been linked to Burushaski.

4. Nivkh is spoken in the lower Amur basin and on the northern half of Sakhalin island. It has a recent modern literature and the Nivkhs have experienced a turbulent history in the last century.

5. Ainu is sometimes added to this group though it is not, strictly speaking, a language of Siberia. It barely survives in southern Sakhalin where it was the main native language. It was also spoken in the Kuril islands and on Hokkaido where a strong interest in its revival is taking place. It has been related by some linguistics to Indo-Pacific languages and Kalto.

Together with Japanese and Korean which are major modern languages, these 'poor relations' resist any easy or obvious linguistic classification, either with other groups or with each other.