Madame John's Legacy is a historic house museum at 632 Dumaine Street in the French Quarter of New Orleans, Louisiana. Completed in 1788, it is one of the oldest houses in the French Quarter, and was built in the older French colonial style, rather than the more current Spanish colonial style of that time. It was declared a National Historic Landmark in 1970 for its architectural significance. The Louisiana State Museum owns the house and provides tours.