Persian Iraq, also uncommonly spelled Persian Irak^[1] (Persian: عراقِ عجم Erāq-e Ajam or عراق عجمی Erāq-e Ajami; Arabic: عراق العجم ʿIrāq al-ʿAjam or العراق العجمي al-ʿIrāq al-ʿAjamī, literally, "Iraq of the Ajam"), is a historical region of the western parts of Iran.

The region, originally known as Media in pre-Islamic times, became known as Jibal ("mountain, hill") by early Islamic geographers, due its mountainous layout. The name was progressively abandoned during the Seljuk era in the 11th-12th centuries, and was called ʿIrāq-i ʿAjam(ī) ("Persian Iraq") to distinguish it from ʿIrāq-i ʿArab(ī) ("Arab Iraq") in Mesopotamia.^[2]

According to the medieval historian and geographer Yaqut al-Hamawi, this course started taking place when the Seljuk sultans ruled both Iraq proper and Jibal, thus being addressed "sultan al-Iraq". However, the city of Hamadan in Jibal eventually became their capital, thus resulting in the region becoming known as Iraq, with the word Ajami ("Persian") being added.^[3] Following the Mongol invasion of Iran in the 13th-century, the name Jibal had become completely outdated. In the following century, the geographer Hamdallah Mustawfi was unaware of the name Jibal, and only knew it as 'Iraq-i Ajami'. It was regarded by him as sardsīr ("cold zone").^[3]

Later, until the beginning of the 20th century, the term Iraq in Iran was used to refer to a much smaller region south of Saveh and west of Qom. This region was centered on Soltanabad, which was renamed later as Arak.^[4]