city, extreme southwestern Iran. The city is situated in Khūzestān, part of the oil-producing region of Iran. Ābādān lies on an island of the same name along the eastern bank of the Shaṭṭ Al-ʿArab (river), 33 miles (53 km) from the Persian Gulf. The city thus lies along Iran's border with Iraq. Ābādān Island is bounded on the west by the Shaṭṭ Al-ʿArab and on the east by the Bahmanshīr, which is an outlet of the Kārūn River. The island is 42 miles (68 km) long and from 2 to 12 miles (3 to 19 km) wide.

Reputedly founded by a holy man, ʿAbbād, in the 8th century, Ābādān was a prosperous coastal town in the ʿAbbāsid period and was known for its salt and woven mats. But the extension of the delta of the Shaṭṭ Al-ʿArab by silt deposition caused the coast of the Persian Gulf to gradually recede from Ābādān. By the time the town was visited by the Arab geographer Ibn Baṭṭūṭah in the 14th century, it was described as little more than a large village in a flat, salty plain.

Persia and the Ottomans long disputed Ābādān's possession, but Persia acquired it in 1847. Its village status remained unchanged until the early 20th century, when rich oilfields were discovered in Khūzestān. In 1909 the Anglo-Persian Oil Company (BP PLC) (its Iranian properties were nationalized in 1951 as the National Iranian Oil Company) established its pipeline terminus refinery at Ābādān. The refinery began operating in 1913, and by 1956 Ābādān had become a city of more than 220,000 inhabitants, with an economy almost entirely based on petroleum refining and shipping. The refinery complex was served by pipelines running from oil fields to the north, and pipelines were subsequently constructed from Ābādān to Tehrān and to Shīrāz. By the late 1970s the city's oil refinery was perhaps the largest in the world.

In September 1980, however, Ābādān was almost overrun in the course of Iraq (Iran-Iraq War)'s surprise invasion of Khūzestān. The Iraqis failed to take Ābādān, but their artillery and aerial bombardments destroyed its refineries and reduced most of the city to rubble. After the Iran-Iraq War ended in 1988, Iran restarted petroleum refining and petrochemical production in Ābādān on a smaller scale using reconstructed plants. The city's port reopened in 1993. Pop. (2006) 219,772.