The Williams-Pratt House, is a roughly 11,040 sq. ft. mansion located in Buffalo, New York, which was built between 1896 and 1899. The house was designed by architect Stanford White of the New York firm of McKim, Mead & White for Charles Howard Williams and his wife Emma. The building is a contributing property to the Delaware Avenue Historic District designated in 1974.

Delaware Avenue Historic District is a national historic district located at Buffalo, New York, United States, and Erie County. It is located along the west side of Delaware Avenue between North Street to the South and Bryant Street to the North.