Lyon Hall, Greek Revival building in Alabama, United States.

Lyon Hall is a two-story wooden frame house in Demopolis, Alabama, clad in clapboard and built in the Greek Revival style. Its front portico carries six two-story square columns of brick finished in stucco, similar to those at nearby Bluff Hall, and the upper balcony runs the full width of the facade. The roof is hipped and topped by a small belvedere.

George Gaines Lyon, an attorney and nephew of Francis Strother Lyon of nearby Bluff Hall, began building the house in 1850 and completed it in 1853. The family then traveled to New York City to furnish it. Lyon descendants lived there until George Gaines Lyon Lamar died in 1996, and the house was donated to the Marengo County Historical Society in May 1997.

The house is also called the Lyon-Lamar House, after the family that kept it for generations. George Gaines Lyon Lamar, a Lyon descendant, lived there until his death in 1996; the following year the house passed to the Marengo County Historical Society. The name Lyon Hall recalls the attorney George Gaines Lyon, nephew of Francis Strother Lyon of nearby Bluff Hall.

Lyon Hall stands in Demopolis, Marengo County, Alabama, at coordinates 32.51575, -87.83922. The house passed to the Marengo County Historical Society in May 1997, so enquiries about seeing the interior go through that society rather than a state parks office. The two-story portico and full-width upper balcony are best viewed from the street, where the six brick-and-stucco columns and the belvedere on the hipped roof can be seen together.

The six two-story portico columns are brick finished with stucco, a detail shared with nearby Bluff Hall, the residence of Lyon's uncle Francis Strother Lyon. The hipped roof carries a small belvedere at its summit. After George Gaines Lyon Lamar died in 1996, the house passed to the Marengo County Historical Society in May 1997.