- Saint Thomas (Danish: Sankt Thomas, Spanish: Santo Tomás, French: Saint-Thomas) is one of the Virgin Islands in the Caribbean Sea, and a constituent district of the United States Virgin Islands (USVI), an unincorporated territory of the United States. Along with surrounding minor islands, it is one of three county-equivalents in the USVI. Together with Saint John, it forms one of the districts of the USVI. The territorial capital and port of Charlotte Amalie is located on the island.