The John Williams House, also known as the Williams Mansion House, is an historic American home that is located near Williams Grove in Cumberland County, Pennsylvania.

It was listed on the National Register of Historic Places in 1977.

History and architectural features

Built between 1799 and 1802, this historic structure is a large, 2+1⁄2-story, limestone building, five bays wide and two bays deep. It has a Georgian floorplan. An extensive interior remodeling took place circa 1825; the house was also then restored in 1970. A porch was added during the mid-nineteenth century.

It was listed on the National Register of Historic Places in 1977.