Aquidneck Island, officially known as Rhode Island, is an island in Narragansett Bay in the state of Rhode Island. The total land area is 37.8 sq mi (98 km2), which makes it the largest island in the bay. The 2020 United States Census reported its population as 60,109. The state of Rhode Island is named after the island; the United States Board on Geographic Names recognizes Rhode Island as the name for the island, although it is widely referred to as Aquidneck Island in the state and by the island's residents.

Narragansett Bay is a bay and estuary on the north side of Rhode Island Sound covering 147 square miles (380 km2), 120.5 square miles (312 km2) of which is in Rhode Island. The bay forms New England's largest estuary, which functions as an expansive natural harbor and includes a small archipelago. Small parts of the bay extend into Massachusetts.