Assyrians in Iran, or Iranian Assyrians, are an ethnic and linguistic minority in present-day Iran. The Assyrians of Iran speak Assyrian Neo-Aramaic, a neo-Aramaic language descended from Classical Syriac and elements of Akkadian, and are Eastern Rite Christians belonging mostly to the Assyrian Church of the East and also to the Ancient Church of the East, Assyrian Pentecostal Church, Chaldean Catholic Church and Assyrian Evangelical Church.

Iraqi Assyrians are an ethnic and linguistic minority group, indigenous to Upper Mesopotamia. They are defined as Assyrians residing in the country of Iraq, or members of the Assyrian diaspora who are of Iraqi-Assyrian heritage. They share a common history and ethnic identity, rooted in shared linguistic, cultural and religious traditions, with Assyrians in Iran, Turkey and Syria, as well as with the Assyrian diaspora elsewhere. A significant number have emigrated to the United States, notably to the Detroit and Chicago; a sizeable community is also found in Sydney, Australia.