Henry Tunis Smith Farm, also known as the Middlebrook Farm, is a historic farmhouse located at Nassau in Rensselaer County, New York. The house was built in 1789 in the Federal style. It consists of a 1+1⁄2-story main block, five bays wide, with a 1-story, three-bay wing. The front facade features a finely detailed frieze. It was listed on the National Register of Historic Places in 1975. The house sits on a historic property that traces back to the 17th century Dutch Manor of Rensselaerswyck The current farm property includes the original parcel leased from Van Rensselaer.