Mark O'Hara House, also known as the W. F. Kuenzel House, is a historic home located at Washington, Franklin County, Missouri. It was built about 1856, and is a large 2+1⁄2-story, five-bay, Federal style brick dwelling on a stone foundation. It has a two-story brick side ell, side-gable roof, and flat topped door and window openings.[2]: 5