Fort St. David, a town of India, on the Coromandel coast, in South Arcot, 3 m. N. of Cuddalore, and 12 m. S. S. W. of Pondicherry. It was formerly well fortified. The town was called Tegnapatam till 1691, when it was purchased by the East India company. It withstood a siege by the French in 1746, and from that period remained for 12 years the capital of the British possessions in this part of India. In 1758 the French under Lally besieged it again, captured it after a short resistance, and destroyed its fortifications. It is now in ruins.