Turkification, Turkization, or Turkicization (Turkish: Türkleştirme) describes a shift whereby populations or places receive or adopt Turkic attributes such as culture, language, history, or ethnicity. However, often this term is more narrowly applied to mean specifically Turkish rather than merely Turkic, meaning that it refers more frequently to the Ottoman Empire's policies or the Turkish nationalist policies of the Republic of Turkey toward ethnic minorities in Turkey. As the Turkic states developed and grew, there were many instances of this cultural shift.

The earliest instance of Turkification took place in Central Asia, when by the 6th century AD migration of Turkic tribes from Inner Asia caused a language shift among the Iranian peoples of the area. By the 8th century AD, the Turkification of Kashgar was completed by Qarluq Turks, who also Islamized the population.

The Turkification of Anatolia occurred in the time of the Seljuk Empire and Sultanate of Rum, when Anatolia had been a diverse and largely Greek-speaking region after previously being Hellenized.

Prior to the 20th century, Anatolian, Balkan, Caucasian, and Middle Eastern regions were said to undergo Ottomanization. "Turkification" started being used interchangeably with "Ottomanization" after the rise of Turkish nationalism in the 20th century.

The term has been used in the Greek language since the 1300s or late-Byzantine era as "εκτουρκισμός", or "τούρκεμα". It literally translates to "becoming a Turk". Apart from people, it may also refer to cities conquered by the Turks or churches converted to mosques. It is more frequently used in the verb form "τουρκεύω" (to Turkify, to become Muslim or Turk).

By 750, the Turkification of Kashgar by the Qarluq Turks was underway. The Qarluqs were ancestors of the Karakhanids, who also Islamized the population. The Iranian language of Khwarezm, a Central Asian oasis region, eventually died out as a result of Turkification.

The current population of Central Asia is the result of the long and complex process that started at least 1,400 years ago. Today this region consists of mainly Turkic ethnic groups, barring Persian-speaking Tajiks, although centuries ago its native inhabitants were Iranian peoples. Turkification of the native Iranian population of Central Asia began by the 6th century A.D. partly due to migration of Turkic tribes from Inner Asia. The process of Turkification of Central Asia, besides those parts that constitute the territory of present-day Tajikistan and parts of Uzbekistan with a majority Tajik population, accelerated with the Mongol conquest of Central Asia. Mahmud al-Kashgari writes that the people who lived between Bukhara and Samarkand were Turkified Sogdians, whom he refers to as “Sogdak”.

Tajiks are considered to be the only ethnic group to have survived the process of Turkification in Central Asia. Despite their clear Iranian ethnicity, some arguments attempt to denounce Tajiks' Iranian identity, and instead link them with the descendants of Arabs raised in Iran or Turks who have lost their language under the influence of Persian civilization.