Jamiat-e-Islami (also rendered as Jamiati Islami; Pashto: د افغانستان اسلامي جمعیت, lit. 'Islamic Society'), sometimes shortened to Jamiat, is a predominantly Afghan Tajik political party and former paramilitary organisation in Afghanistan. It was the largest functioning paramilitary in Afghanistan, with 5,000 cadres and 30,000 supporters, and was originally formed as a student political society at Kabul University. It has a communitarian ideology based on Islamic law. During the Soviet–Afghan War and the subsequent First Afghan Civil War against the communist government, Jamiat-e Islami was one of the most powerful of the Afghan mujahideen groups. Burhanuddin Rabbani led the party (including its predecessors) from 1968 to 2011, and served as President of the Islamic State of Afghanistan from 1992 to 2001, in exile from 1996.

Jamiat "emerged" in 1972 from among "the informal Islamist groupings that had existed since the 1960s". Led by Burhanuddin Rabbani, a professor of Islamic theology at Kabul University, it was inspired by Abul A'la Maududi and his Jamaat-e-Islami Pakistan. When Rabbani's arrest was ordered by Mohammad Daoud Khan in 1973, it was to Pakistan that Rabbani fled, and Jamaat-e-Islami who initially hosted him there. (Later Jamait lost the backing of Jamaat-e-Islami to the more purist Hezb-i Islami.)

In Pakistan, Professor Rabbani gathered important people and continued to build the party. Sayed Noorullah Emad, who was then a young Muslim at Kabul University became its general secretary and, later, its deputy chief. Some of its prominent commanders included Ustad Zabihullah], Gulbadin Hekmatyar, Ahmad Shah Massoud, Ismail Khan, Atta Muhammad Nur, Mullah Naqib and Dr. Fazlullah. Ahmad Shah Massoud directed the military wing of the party.

Ahmad Shah Massoud and Gulbuddin Hekmatyar were both early followers of Rabbani, being Kabul University students at the time. Hekmatyar broke away from Jamiat in 1976 to found his own party: Hezb-e Islami.

The two groups formed the two main tendencies of the Islamist movement in Afghanistan, and after the April 1978 coup and the brutality of the invading Soviet Army, the two strongest Afghan mujahideen groups in the 1980s.

Rabbani and the Jamiat advocated "building of a widely based movement that would create popular support", a gradualist strategy of infiltration of society and the state apparatus to gain power. Jamiat was dominated by Tajiks but had a greater `tribal and regional cross section` than other groups, and was willing to seek "common ground" with non-Islamists. It gained prominence because of the battlefield success of Ahmad Shah Massoud.

Hezb-i Islami was overwhelmingly Ghilzai Pashtun, and backed by Pakistan president Zia ul-Haq. Its leader, Hekmatyar, was "implacably hostile to any form of compromise" favouring violent armed conflict. As a result, Hezb-i Islami, and not Jamiat, gained the support of the Muslim Brotherhood, Jamaat-e-Islami Pakistan, and Saudi Arabian networks.

After the Soviet invasion in Afghanistan in 1979, Massoud organised a mujahideen group in Parwan Province to fight against the Communist government and their Soviet allies. This group grew to control multiple provinces and include thousands of fighters. The Soviet Army launched a series of major offensives to attempt to destroy their forces, but they were unable to engage most of Massoud's men.^{[citation needed]}