Tajik may refer to:

• Tajiks, an ethnic group living in Afghanistan, Tajikistan, Uzbekistan, Iran, Pakistan, and China
• The Tajik language, the official language of Tajikistan
• The Arabic-schooled, ethnically Persian administrative caste of the Turco-Persian society.

note: inhabitants of Tajikistan, and the related adjective are Tajikistani(s)

Tajik is occasionally written as Tadzhik or Tadjik due to an incorrect translation from Russian.