Squirrel Island is a small island in the Gulf of Maine, part of the town of Southport. It was founded as a summer community in 1871 and has about 100 cottages. The island has no cars, stores, or medical facilities, but it has a restaurant, library, chapel, tennis courts, and beaches. The island is connected to the mainland by a ferry boat that runs from Boothbay Harbor. Squirrel Island is named for its shape, not for its wildlife.

The Maine By Foot website has a description and map of a hike at Squirrel Island.