The Iranian Azerbaijan or Iranian Azarbaijan (Persian: آذربایجان ایران; Āzarbāyjān-e Irān) is a region in the northwest of Iran, approximately consisting of the provinces of Ardabil, East Azarbaijan, and West Azarbaijan.

This is the area that was historically named Azarbaijan/Azerbaijan, from which the Republic of Azerbaijan (which became the Azerbaijan SSR later and then the Republic of Azerbaijan again) took its name when it was formed as independent state with the help of the Ottomans in 1918. The new republic consisted of three former Persian provinces of Aran, Shervan and Talish-i Gushtasbi which were taken by Russia in the Persia-Russia Wars . Many Iranian scholars of the time, including Mohammad Taghi Bahar and Ali Akbar Dehkhoda heavily protested to this name transfer, mentioning that it will create a case for territorial claims on Iranian Azarbaijan, which it did during the Soviet era, and still persists by pan-Turkist political activists who call the Iranian Azerbaijan "South Azerbaijan". The term is considered historically inaccurate and very biased, and is rarely used by people who are not working for the secession of the region or its unification with the Republic of Azerbaijan.

Iranian Azerbaijan has an area of 176,512 sq km and a population of 28 million. Iranian Azarbaijan is famous for its great nature beauty. There are 17 rivers and two lakes in the region. Cotton, nuts, textiles, tea, machinery and electrical equpiments are main industries.

Major cities include Tabriz, Uromieh, Ardabil, Maragheh and Marand.