Allen Island or Allen's Island is a  private island which is part of St. George, Knox County, Maine. In 1979, it was purchased by Betsy Wyeth, wife of painter Andrew Wyeth. The Island had lost its full-time residents when it was purchased by Wyeth and had become "a seasonal home for two fishing families living in decaying houses on the fringe of the fast-encroaching spruce forest". It was added to the National Register of Historic Places on December 15, 1983.