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").

The Tajiks of China, although known by the name Tajik, speak Eastern Iranian languages and are distinct from Persian Tajiks.

Ahmad Shah Massoud (احمد شاه مسعود Aḥmad Šāh Mas'ūd; September 2, 1953 – September 9, 2001) was a political and military leader in Afghanistan. He was a central figure, known as the "Lion of Panjshir", in the resistance against the Soviet occupation between 1979 and 1989, fought against the alliance of Gulbuddin Hekmatyar in the early 1990s, and led resistance against the Taliban regime between 1996 and 2001. Massoud was assassinated on September 9, 2001, two days before the attacks of September 11.

Massoud was an Afghan-Tajik Sunni Muslim born in the Panjshir in northern Afghanistan. He studied engineering at Kabul University in the 1970s, where he became involved with Muslim anti-communist movements around Burhanuddin Rabbani. He led an uprising against the Soviet-backed communist government in his native Panjshir in 1979. His role in the following period of armed resistance against the Soviet occupation forces earned him the nickname of "Lion of Panjshir" (شیر پنجشیر). Following the withdrawal of Soviet troops from Afghanistan the Wall Street Journal named Massoud "the Afghan who won the Cold War". In 1992, he was appointed minister of defense in the government of the newly established Islamic State of Afghanistan by the peace and power-sharing agreement Peshawar Accords. He led the Islamic State's defense against attacks by Gulbuddin Hekmatyar's alliance of militias which were backed by Pakistan. Following the rise of the Taliban in 1996, Massoud, who rejected the Taliban's and Al-Qaeda's extremist interpretation of Islam, returned to the role of an armed opposition leader, serving as the military and political leader of the multiethnic United Islamic Front (also known in the West as Northern Alliance). In 1997, he helped end the civil war in neighboring Tajikistan urging parties to accept a United Nations peace plan.