Ahvaz (, Khuzestani Arabic: أهواز Aẖwaz) is a city in the southwest of Iran. At the 2011 census, its population was 1,112,021 and its built-up (or metro) area with Sheybany was home to 1,136,989 inhabitants. Ahvaz has the world's worst air pollution according to a survey by the World Health Organization in 2011.
Ahvaz is built on the banks of the Karun River and is situated in the middle of Khuzestan Province, of which it is the capital and most populous city. The city has an average elevation of 20 meters above sea level.