Several important religions and religious movements originated in Greater Iran, that is, among speakers of various Iranian languages and hence with an Iranian cultural background.
- Zurvanism: By late Achaemenid times, Zoroastrianism was also evident as Zurvanism (Zurvanite Zoroastrianism), a monist dualism that had a following as late as the Sassanid era.
- Mandaeism: A gnostic monotheism of (at the latest) the 1st century CE observed Mandā d-Heyyi - "Knowledge of Life". Mandaean theology is based more on a common heritage than on any set of religious creeds and doctrines.
- Manichaeism: 3rd century ditheistic gnosticism that may have been influenced by Mandaeism. Manichaens believed in a "Father of Greatness" (Aramaic: Abbā dəRabbūṯā, Persian: pīd ī wuzurgīh) and observed Him to be the highest deity (of light).
- Mazdakism: A late 5th/early 6th century proto-socialist gnosticism that sought to do away with private property.
Medieval period 
- The early Islamic period saw the development of Persian mysticism, a traditional interpretation of existence, life and love with Perso-Islamic Sufi monotheism as its practical aspect. This development believed in a direct perception of spiritual truth (God), through mystic practices based on divine love.
- Khurramites, a 9th century religious and political movement based on the 8th century teachings of Sunpadh, who preached a syncretism of Shia Islam and Zoroastrianism. Under Babak Khorramdin, the movement sought the redistribution of private wealth and the abolition of Islam.
- Behafaridians, an 8th century cult movement around the self-acclaimed prophet Behafarid. Although the movement is considered to have its roots in Zoroastrianism, Behafarid and his followers were executed on charges (made by Zoroastrians) of harm to both Zoroastrianism and Islam.
- Yarsan, a religious order of Yazdanism, which is believed to have been founded in the 16th century. Yazdanism promulgated the belief in a God manifest as one primary and five secondary avatars to form with God the Holy Seven.
- Alessandro Bausani, Religion in Iran: From Zoroaster to Bahaullah, Bibliotheca Persica, 2000
- Richard Foltz,Spirituality in the Land of the Noble: How Iran Shaped the World's Religions, Oneworld publications, 2004