Afghan refugees are Afghanistan nationals who fled their country as a consequence of the long-going Afghan conflict, lasting since 1978. Ever since the Soviet invasion of Afghanistan, refugees have fled into the surrounding states. After the Soviets left, civil war, Taliban conquest, and most recently the Western-led invasion after September 11, 2001 have meant constant warfare in Afghanistan. Millions have fled the violence, then in times of relative peace returned, only to flee again when renewed fighting broke out. About six million Afghan refugees have fled to neighboring Pakistan (mainly Khyber Pakhtunkhwa province) and Iran, making Afghanistan the largest refugee-producing country in the world, a title it has held for 32 years. The mass majority of Afghan refugees (95%) are located in either Iran or Pakistan. Some NATO countries that were part of the NATO forces took in refugees or Afghans that worked with their respective forces. Ethnic minorities, like Afghan Sikhs and Hindus, often fled to India.

Afghan diaspora or Afghan immigrants are citizens of Afghanistan who have immigrated to other countries, or people of Afghan origin who are born outside Afghanistan. Traditionally, the borders between Afghanistan and its southern and eastern neighbouring countries have been fluid and vague. Like other nations that were created by European empires, the borders of Afghanistan with neighboring countries often do not follow ethnic divisions, and several native ethnic groups are found on both sides of Afghanistan's border. This means that historically there was much movement across present day barriers.