Turks (Turkish: Türkler), or Turkish people, are the largest Turkic ethnic group, comprising the majority of the population of Turkey and Northern Cyprus. They generally speak the various Turkish dialects. In addition, centuries-old ethnic Turkish communities still exist across other former territories of the Ottoman Empire. Article 66 of the Constitution of Turkey defines a Turk as anyone who is a citizen of the Turkish state. While the legal use of the term Turkish as it pertains to a citizen of Turkey is different from the term's ethnic definition, the majority of the Turkish population (an estimated 70 to 75 percent) are of Turkish ethnicity. The vast majority of Turks are Sunni Muslims, with a notable minority practicing Alevism.

The ethnic Turks can therefore be distinguished by a number of cultural and regional variants, but do not function as separate ethnic groups. In particular, the culture of the Anatolian Turks in Asia Minor has underlain and influenced the Turkish nationalist ideology. Other Turkish groups include the Rumelian Turks (also referred to as Balkan Turks) historically located in the Balkans; Turkish Cypriots on the island of Cyprus, Meskhetian Turks originally based in Meskheti, Georgia; and ethnic Turkish people across the Middle East, where they are also called Turkmen or Turkoman in the Levant (e.g. Iraqi Turkmen, Syrian Turkmen, Lebanese Turkmen, etc.). Consequently, the Turks form the largest minority group in Bulgaria, the second largest minority group in Iraq, Libya, North Macedonia, and Syria, and the third largest minority group in Kosovo. They also form substantial communities in the Western Thrace region of Greece, the Dobruja region of Romania, the Akkar region in Lebanon, as well as minority groups in other post-Ottoman Balkan and Middle Eastern countries. The mass immigration of Turks also led to them forming the largest ethnic minority group in Austria, Denmark, Germany, and the Netherlands. There are also Turkish communities in other parts of Europe as well as in North America, Australia and the Post-Soviet states. Turks are the 13th largest ethnic group in the world.

Turks from Central Asia settled in Anatolia in the 11th century, through the conquests of the Seljuk Turks. This began the transformation of the region, which had been a largely Greek-speaking region after previously being Hellenized, into a Turkish Muslim one. The Ottoman Empire expanded into parts of West Asia, Southeast Europe, and North Africa over the course of several centuries. In the 19th and early 20th centuries, persecution of Muslims during the Ottoman contraction and in the Russian Empire resulted in large-scale loss of life and mass migration into modern-day Turkey from the Balkans, Caucasus, and Crimea; the immigrants were both Turkish and non-Turkish people, and overwhelmingly Muslim. The empire lasted until the end of the First World War, when it was defeated by the Allies and partitioned. Following the Turkish War of Independence that ended with the Turkish National Movement retaking much of the territory lost to the Allies, the Movement ended the Ottoman Empire on 1 November 1922 and proclaimed the Republic of Turkey on 29 October 1923.

As an ethnonym, the etymology of Turk is still unknown. In Chinese sources, Turk appears as Tujue (Chinese: 突厥; Wade–Giles: T'u-chüe), which referred to the Göktürks. The earliest mention of Turk (𐱅𐰇𐰺𐰜, türü̲k̲; or 𐱅𐰇𐰼𐰚, türk/tẄrk) in Turkic languages comes from the Second Turkic Khaganate. In Orkhon inscriptions, kök türü̲k̲ (𐰚𐰇𐰚 𐱅𐰇𐰼𐰜) is also mentioned, potentially referring to "Ashina-led Turks" or "Ashinas and Turks".

There are several theories regarding the origin of the ethnonym Turk. There is a claim that it may be connected to Herodotus's (c. 484 – c. 425 BC) reference to Targitaos, (Ταργιτάος), a king of the Scythians; however, Manfred Mayrhofer (apud Lincoln) assigned Iranian etymology for Targitaos: from Old Iranian *darga-tavah, meaning "he whose strength is long-lasting". During the first century A.D., Pomponius Mela refers to the Turcae in the forests north of the Sea of Azov, and Pliny the Elder lists the Tyrcae among the people of the same area; yet English archaeologist Ellis Minns contended that Tyrcae is "a false correction" for Iurcae/Iurkai (Ἱύρκαι), a people who dwelt beyond the Thyssagetae, according to Herodotus (Histories, IV. 22) There are references to certain groups in antiquity whose names might have been foreign transcriptions of Tür(ü)k such as Togarmah, Turukha/Turuška, Turukku and so on; but according to American historian Peter B. Golden, while any connection of some of these ancient peoples to Turks is possible, it is rather unlikely.

As a word in Turkic languages, Türk may mean 'strong, strength, ripe' or 'flourishing, in full strength'. It may also mean ripe as for a fruit or "in the prime of life, young, and vigorous" for a person. Róna-Tas (1991) pointed to a Khotanese-Saka word, tturakä 'lid', semantically stretchable to 'helmet', as a possible source for this folk etymology, yet Golden thinks this connection requires more data.

In the 19th century Ottoman Empire, the word Türk referred to Anatolian peasants. The Ottoman ruling class identified themselves as Ottomans, not as Turks. However, they still claimed to be members of Kayi tribe of Oghuz Turks and direct descendants of Oghuz Khan. In the late 19th century, as the Ottoman upper classes adopted European ideas of nationalism, the term Türk took on a more positive connotation.

During Ottoman times, the millet system defined communities on a religious basis. In the early 20th century, the Young Turks abandoned Ottoman nationalism in favor of Turkish nationalism, while adopting the name Turks, which was finally used in the name of the new Turkish Republic.