The Former Caswell Public Library is an historic building at 42 Main Street in Harrison, Maine. Built in 1908-09, it is one of the small community's most architecturally distinctive buildings, designed in the Romanesque Revival style by a local architect. It is named for Daniel Caswell, a generous benefactor to the library, and housed the local public library until 2004. It was listed on the National Register of Historic Places in 2005. The building is presently vacant.