Coordinates: 26°40′41″N 77°07′44″W / 26.678°N 77.129°W
Great Guana Cay is an islet in The Bahamas. It is a long, narrow islet, 7 miles (11 km) long. It is in the centre of the Abaco Islands and is near Gumelemi Cay. It is about 8 miles from Marsh Harbour. Approximately 150 people live on the island, mostly along the five and a half mile long stretch of beach.
Great Guana Cay's settlement is known for its loyalist culture and architecture, as well as its social scene. Several traditional loyalist homes are in the settlement, which wraps around a natural harbor.
Great Guana Cay is an Abaco barrier island that hosts elkhorn and staghorn coral reefs. It also contains a large amount of virgin forest, where migrating birds and Abaco endemic species live. Loggerhead sea turtles, green sea turtles and hawksbill sea turtles nest on the island's beaches. Both white-crowned pigeons and white-tailed tropicbirds nest on the island. Before removal of the crabbing-ground mangroves by a golf development, land crabs such as were common and were hunted for food by the native population.
A cove on the island called Kidd's Cove was named after the pirate William Kidd.