The Athens metropolitan area (Greek: Μητροπολιτική Περιοχή της Αθήνας) spans 2,928.717 km (1,131 sq mi) within the Attica region and consists of 58 municipalities plus parts of East Attica and West Attica, having reached a population of 4,073,179 according to the 2021 census. The municipalities of Athens and Piraeus both serve as the two metropolitan centres of the Athens metropolitan area.
According to the Hellenic Telecommunications and Post Commission, the Athens metropolitan area consists of all areas with a dialing code of 21 and includes areas such as Salamina, Elefsina, Kifissia, Mandra, Magoula,Aspropyrgos, Pallini, Agios Stefanos, Dionysos, Parnitha, Koropi, Vari, Vouliagmeni, Voula and the Athens International Airport.