town and chief port of Kenya, on a coralline island in a bay of the Indian Ocean. The island is linked to its mainland municipal territory of 100 square miles (259 square km) by causeway, bridge, and ferry and has an area of 5.5 square miles (14.25 square km).

Founded by Arab traders in the 11th century, Mombasa was an important port for trade across the Indian Ocean. It was visited in 1331 by the Arab traveler Ibn Baṭṭūṭah and in 1498 by the Portuguese navigator Vasco da Gama (Gama, Vasco da). Because of its strategic position, it was continually fought over, passing among the Arabs, Persians, Portuguese, and Turks until 1840, when the sultan of Zanzibar finally gained control. It came under British administration in 1895 and was capital of the East Africa Protectorate until 1907. Mombasa became a municipality in 1928 and assumed council status in 1959.

Mombasa has two ports, Mombasa Old Port on the island's east side and Kilindini Harbour on the west. The old port is now used only by dhows and small craft, bringing trade from Arabia, the Persian Gulf, and India. The old city is strongly Middle Eastern, with narrow streets, high houses with carved ornamental balconies, and mosques and temples. It is the site of Fort Jesus, built by the Portuguese (1593–95) and now a museum. There are Anglican and Roman Catholic cathedrals. A Hindu temple built in 1952 has a gilded dome. Mombasa's many historical and cultural attractions have made it a popular tourist destination.

Kilindini is a modern deepwater port of numerous berths in a landlocked anchorage. Mombasa serves as the market for the region's agricultural products (sisal, cotton, sugar, kapok, coconuts, fruits, and vegetables), and it exports many of these as well as the products of northeastern Tanzania and Uganda, with which it is connected by rail. Industries include shipbuilding and repair, metal and cement works, sugar processing, a fertilizer plant, and an oil refinery (1963) at Changamwe. Pop. (2004 est.) 777,100.