The People's Mojahedin Organization of Iran (PMOI), also known as Mojahedin-e-Khalq (MEK) or Mojahedin-e-Khalq Organization (MKO), is an Iranian dissident organization that was previously armed but has now transitioned primarily into a political advocacy group. Its headquarters are currently in Albania. The group's ideology is rooted in "Islam with revolutionary Marxism," but after the Iranian Revolution became about overthrowing the Government of the Islamic Republic of Iran and installing its own government. At one point the MEK was Iran's "largest and most active armed dissident group," and it is still sometimes presented by Western political backers as a major Iranian opposition group, but it is also deeply unpopular today within Iran, largely due to its siding with Iraq in the Iran–Iraq War.

The Iranian Revolution, also known as the Islamic Revolution, was a series of events that culminated in the overthrow of the Pahlavi dynasty in 1979. The revolution also led to the replacement of the Imperial State of Iran by the present-day Islamic Republic of Iran, as the monarchical government of Mohammad Reza Pahlavi was superseded by the theocratic government of Ayatollah Ruhollah Khomeini, a religious cleric who had headed one of the rebel factions. The ousting of Pahlavi, the last Shah of Iran, formally marked the end of Iran's historical monarchy.