The Hathaway Barn is a historic barn at 135 Nortons Corner Road in Willimantic, Maine, a rural community in southern Piscataquis County. Built c. 1880 by Jabez Hathaway, this large barn was an optimistic expression of the future prospects of the dairy industry in the area, which were ultimately not borne out. The barn is part of a farmstead complex whose other elements have not maintained historical integrity; it was listed on the National Register of Historic Places in 2003.