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.

The Kyrgyz (also spelled Kirgiz, Kirghiz) are a Turkic people living primarily in Kyrgyzstan.

There are several etymological theories on the ethnonym "Kyrgyz."

The word "Kyrgyz" is derived from the Turkic word "forty", with -Iz being an old plural suffix, referring to a collection of forty tribes.