Dammam is the capital of the Eastern Province of Saudi Arabia, the most oil-rich region in the world. The judicial and administrative bodies of the province and several government departments are located in the city. Dammam is the largest city in the Eastern Province and forms part of the greater Dammam metropolitan area along with Dhahran and Khobar, which together have a combined population of over 2,500,000.and the fifth largest in Saudi Arabia, after Riyadh, Jeddah, Mecca and Medina. It is an important commercial hub and port.
Dammam, and the rest of the Eastern Province, is served by the King Fahd International Airport (KFIA), the largest airport in the world in terms of land area (approximately 780 km), about 20 km to the northwest of the city.
Dammam's King Abdul Aziz Sea Port is the largest on the Persian Gulf. Its import-export traffic in the country is second only to Jeddah’s port