Turkmen (türkmençe, türkmen dili, Cyrillic: түркменче, түркмен дили, Persian: تورکمن ﺗﻴﻠی, تورکمنچه) is the national language of Turkmenistan. It is spoken by approximately 7,000,000 people in Turkmenistan, and by an additional approximately 380,000 in northwestern Afghanistan and 500,000 in northeastern Iran.

Turkmen is in the Turkic Language Family. It is a member of the southwestern Turkic sub-branch, more specifically the East Oghuz group. This group also includes Khorasani Turkic. Turkmen is closely related to Turkish and Azerbaijani, with which it is for the most part mutually intelligible.

Turkmen has vowel harmony, is agglutinative, and has no grammatical gender or irregular verbs. Word order is subject–object–verb.

Written Turkmen today is based on the Teke (Tekke) dialect. The other dialects are Nohurly, Yomud, Änewli, Hasarly, Nerezim, Gökleň, Salyr, Saryk, Ärsary and Çowdur. The Teke dialect is sometimes (especially in Afghanistan) referred to as "Chagatai", but like all Turkmen dialects it reflects only a limited influence from classical Chagatai.

The Turkmen (Turkmen: Türkmen/Түркмен, plural Türkmenler/Түркменлер) are a Turkic people located primarily in the Central Asian states of Turkmenistan, Afghanistan, northeastern Iran, Syria, Iraq and North Caucasus (Stavropol Krai). They speak the Turkmen language, which is classified as a part of the Western Oghuz branch of the Turkic languages family together with Turkish, Azerbaijani, Qashqai, Gagauz and Salar.

Originally, all Turkic tribes that were not part of the Turkic dynastic mythological system (for example, Uigurs, Karluks, Kalaches and a number of other tribes) were designated "Turkmens". Only later did this word come to refer to a specific ethnonym. The etymology of the term derives from Türk plus the Sogdian affix of similarity -myn ,-men, and means "resembling a Türk" or "co-Türk". A prominent Turkic scholar, Mahmud Kashgari, also mentions the etymology Türk manand (like Turks). The language and ethnicity of the Turkmen were much influenced by their migration to the west. Kashgari calls the Karluks Turkmen as well, but the first time the etymology Turkmen was used was by Makdisi in the second half of the 10th-century AD. Like Kashgari, he wrote that the Karluks and Oghuz Turks were called Turkmen. Some modern scholars have proposed that the element -man/-men acts as an intensifier, and have translated the word as "pure Turk" or "most Turk-like of the Turks". Among Muslim chroniclers such as Ibn Kathir the etymology was attributed to the mass conversion of two hundred thousand households in AH 349 (971 CE), causing them to be named Turk Iman, which is a combination of "Turk" and "Iman" إيمان (faith, belief), meaning "believing Turks", with the term later dropping the hard-to-pronounce hamza.