The Old Colony House, also known as Old State House or Newport Colony House, is located at the east end of Washington Square in the city of Newport, Rhode Island, United States. It is a brick Georgian–style building completed in 1741, and was the meeting place for the colonial legislature. From independence in 1776 to the early 20th century the state legislature alternated its sessions between here and the Rhode Island State House in Providence.

It has not been altered much since its construction. As one of the best-kept surviving Georgian public buildings in the United States from the colonial era, it was designated a National Historic Landmark (NHL) in 1960.^[3] It is also a contributing property to the Newport Historic District, later designated an NHL itself. It is still owned by the state, but managed as a museum by the Newport Historical Society.

Besides its political and architectural importance, the building was the site of many important Revolutionary events in Rhode Island. George Washington^[2] and Dwight Eisenhower have both been guests at the building. It has been used as a barracks, hospital, courthouse and a location for a Steven Spielberg film.