Prudence Island
41°37′01″N 71°18′59″W / 41.6170°N 71.3164°W
Prudence Island is the third-largest island in Narragansett Bay (after Aquidneck Island and Conanicut Island) in the state of Rhode Island and part of the town of Portsmouth, Rhode Island, United States. Prudence Island is also the largest island in the Bay without road access to the mainland. It is accessible year-round via a ferry service operating from Bristol, Rhode Island.
The island is located near the geographic center of the bay. It is defined by the United States Census Bureau as Block Group 3, Census Tract 401.03 of Newport County, Rhode Island. As of the 2010 census, the population was 278 people living on a land area of 14.43 km2 (5.57 sq mi).