Rosalie Mansion is a historic pre-Civil War mansion and historic house museum in Natchez, Mississippi. Built in 1823, it served as the architectural inspiration for a large number of Natchez's grand Greek Revival mansions, and was a major influence on Antebellum architecture in the greater region. During the American Civil War, it served as Union headquarters for the Natchez area from July 1863 on. It was designated a National Historic Landmark in 1989.