Chennai (chĕn´nī), formerly Madras (mədrăs´, mədräs´), city (1991 pop. 5,421,985), capital of Tamil Nadu state, SE India, on the Bay of Bengal. A commercial, railway, and manufacturing center, Chennai has large textile mills, chemical plants, and tanneries and is the main center of India's automobile industry. Providing offshore and back-office services to foreign corporations is also an important industry. Together with docks and warehouses, its harbor provides modern transportation linkages to peninsular India. A cultural center, the city is the seat of the Univ. of Madras (1857), institutes of dance and music, and a number of museums. There are many large public buildings; a famous shore drive, the Marina; and Guindy National Park. Near Chennai is Mt. St. Thomas, the traditional site of the martyrdom (AD 68) of St. Thomas, the apostle. He is said to be buried in Chennai at the Cathedral of St. Thomé.
The city, as Madras, became an important British trading center, growing largely around Fort St. George, a British outpost (1645) at the site of an earlier British settlement (1639) that became the seat of the British East India Company until 1773 and the capital of the Madras presidency (1653). The French captured Madras in 1746, but the British recovered it two years later. The presidency became a province (1937) and, with Indian independence, a state (1950), renamed Tamil Nadu in 1969. In 1996 the city was renamed Chennai, after Chennapatnam, a precolonial village near the original British outpost. Coastal areas of the city were hit by the Dec., 2004, Indian Ocean tsunami.