The Warren Island State Park is a state park and recreation area in Isleboro, Maine. It is best known for being the first unit in the Maine State Parks system to be ever built solely for boating enthusiasts.

Acquired through the generous gift of the people of Islesboro in 1959, the Warren Island State Park is an island park, only accessed by private boats. There are no public ferries that provide transportation to the park, so anyone interested in visiting this secluded site will need to have their own to get there. When you?re already at the site, you can enjoy a great amount of outdoor recreation. Camping is popular at the site, as well as fishing, hiking, picnicking, sea kayaking, and wildlife viewing.