Port of Spain is a city.
Port of Spain is the capital city of the Republic of Trinidad and Tobago and the country 's third-largest municipality , after Chaguanas and San Fernando . The city has a municipal population of 37,074 ( 2011 census ) , a metropolitan population of 128,026 ( 1990 unofficial estimate ) and a transient daily population of 250,000 . The city serves primarily as a retail and administrative centre and it has been the capital of the island since 1757 . The city is also home to the largest container port on the island and is one of several shipping hubs of the Caribbean , exporting both agricultural products and manufactured goods . Today , Port of Spain is a leading city in the Caribbean region .