The Abbot House, also known as the Abbot-Spalding House, is a historic house museum at One Abbot Square in Nashua, New Hampshire. Built in 1804, it is one of the area's most prominent examples of Federal period architecture, albeit with substantial early 20th-century Colonial Revival alterations. The house was listed on the National Register of Historic Places in 1980, and the New Hampshire State Register of Historic Places in 2002. It is now owned by the Nashua Historical Society, which operates it as a museum; it is open by appointment.