Marion duPont Scott (May 3, 1894 – September 4, 1983) was a thoroughbred horsebreeder who operated a racing stable for both flat and steeplechase racing. She was the last private owner of Montpelier, the mansion and land estate of former United States President James Madison.
At the time of her death, she bequeathed Montpelier to the National Trust for Historic Preservation and established an endowment for its maintenance; it had been designated a National Historic Landmark. During the National Trust's 2003–2008 major restoration of the mansion to its design during the time of Madison's residency, the house was reduced from the 55-room structure developed by the du Pont family back to its original 22 rooms.