town, southwestern Iran. Ahvāz is situated on both banks of the Kārūn River where it crosses a low range of sandstone hills. The town has been identified with Achaemenid Tareiana, a river crossing on the royal road connecting Susa, Persepolis, and Pasargadae. Ardashīr I, the Sāsānian king (224–241) who rebuilt the town, named it Hormuzd Ardashīr. He dammed the river, providing irrigation water, and the town prospered. When the Muslim Arabs conquered it in the 7th century, they renamed it Sūq al-Ahwāz (“Market of the Hūzī”). Ahwāz is the plural of Hūzī, or Khūzī, a local warlike tribe that gave its name to the historical region of Khūzestān. Arab historians of the 12th century described Ahwāz as the centre of a large sugarcane and rice-growing area irrigated by a system of great canals from a dam constructed across the river on solid rock. Ahvāz had begun to decline in the 19th century when the dam collapsed and nearly destroyed the town. The discovery of oil in Khūzestān in the 20th century brought new prosperity to Ahvāz, however.

Because of its location near the border with Iraq, Ahvāz was heavily bombarded during the Iran-Iraq War (1980–90). Nonetheless a steel complex west of the town began operating in 1989. Ahvāz is a junction of two branches of the Trans-Iranian Railway. It is also connected with Ābādān, Khorramshahr, Shūshtar, Dezfūl, and the oil fields by road and with Tehrān by air. Shahid Chamran University (1955; formerly Jundi Shapūr University) is located there. Pop. (2006) 985,614.