town and port, Sri Lanka, on the island's northeastern coast. It is situated on a peninsula in Trincomalee Bay—formerly called Koddiyar (meaning “Fort by the River”) Bay—one of the world's finest natural harbours.

Trincomalee was in early times a major settlement of Indo-Aryan immigrants, who built the Temple of a Thousand Columns at the extremity of the peninsula. The first Europeans to occupy the town were the Portuguese in the 17th century; they razed the temple, using its stone to construct a fort. The port's harbour changed hands repeatedly among the Dutch, French, and British until the British gained lasting possession of it in 1795. Trincomalee's importance as a major British base was heightened after the Japanese ousted the British from Singapore in World War II; the Japanese bombed the town in 1942. The British continued to hold the harbour after Sri Lanka's independence but relinquished it in 1957.

The port of Trincomalee is no longer important commercially, though in the 1960s congestion and labour problems at Colombo, Sri Lanka's commercial capital and chief port, caused some trade to be routed through it. Tourism has become an important component of the local economy. The town is a rail terminus and has good road connections with the rest of Sri Lanka. In December 2004 a large tsunami triggered by an undersea earthquake near Indonesia killed hundreds of people in Trincomalee and caused widespread destruction there. Pop. (1994 est.) 76,000.