Tajik (Persian: تاجيک‎, Tājīk; Tajik: Тоҷик) is a general designation for a wide range of Persian-speaking people of Iranic origin, with traditional homelands in present-day Afghanistan, Tajikistan, and Uzbekistan. There are also smaller communities living in Iran and Pakistan; consisting mainly of refugees from Afghanistan and immigrants from Tajikistan.

In terms of language, culture, and history the Tajiks are closely related to the Persians of Iran.

As a self-designation, the term Tajik, which earlier on had been more or less pejorative, has become acceptable only during the last several decades, particularly as a result of Soviet administration in Central Asia. Alternative names for the Tajiks are Fārsī (Persian), Fārsīwān (Persian-speaker), and Dīhgān (cf. Tajik: Деҳқон, Dehqon, literally "farmer or settled villager", in a wider sense "settled" in contrast to "nomadic").