Jamestown is a town in Newport County, Rhode Island in the United States. The population was 5,405 at the 2010 census. Jamestown is situated almost entirely on Conanicut Island, the second largest island in Narragansett Bay. It also includes the uninhabited Dutch Island and Gould Island. Jamestown is ranked as the 444th wealthiest place to live in the United States as of 2016, with a median home sale price of $1,229,039.
According to the United States Census Bureau, the town has an area of 35.3 square miles (91 km2), of which 9.7 square miles (25 km2) is land and 25.6 square miles (66 km2) is water. The total area is 72.55% water.
Rhode Island Route 138 is the only state highway in Jamestown, connecting the town and island to North Kingstown to the west (over the Jamestown Verrazzano Bridge) and Newport to the east (over the Newport Bridge).
In 1524, Italian navigator Giovanni da Verrazzano and his crew visited Narragansett Bay. Dutch Island was used by fur traders c. 1622, and English colonists made arrangements to use Conanicut Island for grazing sheep in 1638.
Ferries were in operation between Conanicut Island and Newport by 1675. In 1678, Conanicut Island was incorporated as the town of Jamestown, when there were about 150 residents.