The Turkic languages are a language family of more than 35 documented languages spoken by the Turkic peoples of Eurasia, from Eastern Europe and Southern Europe to Central Asia, East Asia, North Asia (Siberia), and West Asia. The Turkic languages originated in a region of East Asia spanning from Mongolia to Northwest China, where Proto-Turkic is thought to have been spoken, and from where they expanded to Central Asia and farther west during the first millennium. They are characterized as a dialect continuum.

Turkic languages are spoken by some 200 million people. The Turkic language with the greatest number of speakers is Turkish, spoken mainly in Anatolia and the Balkans; its native speakers account for about 38% of all Turkic speakers, followed by Uzbek.

Characteristic features such as vowel harmony, agglutination, subject-object-verb order, and lack of grammatical gender, are almost universal within the Turkic family. There is a high degree of mutual intelligibility, upon moderate exposure, among the various Oghuz languages, which include Turkish, Azerbaijani, Turkmen, Qashqai, Chaharmahali Turkic, Gagauz, and Balkan Gagauz, as well as Oghuz-influenced Crimean Tatar. Other Turkic languages demonstrate varying amounts of mutual intelligibility within their subgroups as well. Although methods of classification vary, the Turkic languages are usually considered to be divided into two branches: Oghur, of which the only surviving member is Chuvash, and Common Turkic, which includes all other Turkic languages.

Turkic languages show many similarities with the Mongolic, Tungusic, Koreanic, and Japonic languages. These similarities have led some linguists (such as Turkologist Talât Tekin) to propose an Altaic language family, though this proposal is widely rejected by historical linguists. Similarities with the Uralic languages even caused these families to be regarded as one for a long time under the Ural-Altaic hypothesis. However, there has not been sufficient evidence to conclude the existence of either of these macrofamilies. The shared characteristics between the languages are attributed presently to extensive prehistoric language contact.

December 15 is declared as "World Turkic Language Family Day" by UNESCO. On 15 December 1893, Orkhon Inscriptions, one of the first Turkic texts were decrypted.

Turkic languages are null-subject languages, have vowel harmony (with the notable exception of Uzbek due to strong Persian-Tajik influence), converbs, extensive agglutination by means of suffixes and postpositions, and lack of grammatical articles, noun classes, and grammatical gender. Subject–object–verb word order is universal within the family. In terms of the level of vowel harmony in the Turkic language family, Tuvan is characterized as almost fully harmonic whereas Uzbek is the least harmonic or not harmonic at all. Taking into account the documented historical-linguistic development of Turkic languages overall, both inscriptional and textual, the family provides over one millennium of documented stages as well as scenarios in the linguistic evolution of vowel harmony which, in turn, demonstrates harmony evolution along a confidently definable trajectory Though vowel harmony is a common characteristic of major language families spoken in Inner Eurasia (Mongolic, Tungusic, Uralic and Turkic), the type of harmony found in them differs from each other; specifically, Uralic and Turkic have a shared type of vowel harmony (called palatal vowel harmony) whereas Mongolic and Tungusic represent a different type.^{[citation needed]}

The homeland of the Turkic peoples and their language is suggested to be somewhere between the Transcaspian steppe and Northeastern Asia (Manchuria), with genetic evidence pointing to the region near South Siberia and Mongolia as the "Inner Asian Homeland" of the Turkic ethnicity. Similarly several linguists, including Juha Janhunen, Roger Blench and Matthew Spriggs, suggest that modern-day Mongolia is the homeland of the early Turkic language. Relying on Proto-Turkic lexical items about the climate, topography, flora, fauna, people's modes of subsistence, Turkologist Peter Benjamin Golden locates the Proto-Turkic Urheimat in the southern, taiga-steppe zone of the Sayan-Altay region.

Extensive contact took place between Proto-Turks and Proto-Mongols approximately during the first millennium BC; the shared cultural tradition between the two Eurasian nomadic groups is called the "Turco-Mongol" tradition. The two groups shared a similar religion system, Tengrism, and there exists a multitude of evident loanwords between Turkic languages and Mongolic languages. Although the loans were bidirectional, today Turkic loanwords constitute the largest foreign component in Mongolian vocabulary.