Iranian Azerbaijanis are Iranians of Azerbaijani ethnicity. Most Iranian Azerbaijanis are bilingual in Azerbaijani and Persian. They are mainly of Iranian descent. They are primarily found in and are native to the Iranian Azerbaijan region including provinces of and in smaller numbers, in other provinces such as Kurdistan, Qazvin, Hamadan, Gilan, Markazi and Kermanshah. Iranian Azerbaijanis also constitute a significant minority in Tehran, Karaj and other regions.

Persian, also known by its endonym Farsi or Parsi, is a Western Iranian language belonging to the Iranian branch of the Indo-Iranian subdivision of the Indo-European languages. Persian is a pluricentric language predominantly spoken and used officially within Iran, Afghanistan, and Tajikistan in three mutually intelligible standard varieties, respectively Iranian Persian, Dari Persian, and Tajiki Persian. It is also spoken natively in the Tajik variety by a significant population within Uzbekistan, as well as within other regions with a Persianate history in the cultural sphere of Greater Iran. It is written officially within Iran and Afghanistan in the Persian alphabet, a derivative of the Arabic script, and within Tajikistan in the Tajik alphabet, a derivative of the Cyrillic script.