Gaineswood is a plantation house in Demopolis, Alabama, United States. The house was completed on the eve of the American Civil War after a construction period of almost twenty years. It is the grandest plantation house ever built in Marengo County and is one of the most significant remaining examples of Greek Revival architecture in Alabama. The house and grounds are currently operated by the Alabama Historical Commission as a historic house museum.
Gaineswood is on the National Register of Historic Places and was designated a National Historic Landmark in 1973. The estate is owned by the state of Alabama and is administered by the Alabama Historical Commission. Severe moisture damage to the ceiling and dome in the dining room was corrected under a Save America's Treasures grant.
The Whitfield family has donated or sold much of the original family furniture and some statuary to the Historical Commission to be used in the house. The Burning of the Eliza Battle, painted by Nathan B. Whitfield, still hangs at Gaineswood. He was a witness to the steamboat disaster in 1858.