Theta Xi Fraternity Chapter House, also known as the Alpha of Theta Xi Fraternity Chapter House, or less formally as The Zoo, is a historic fraternity house associated with Rensselaer Polytechnic Institute and located at 1490 Sage Avenue in Troy, Rensselaer County, New York. It was built in 1931 as a chapter house for Theta Xi fraternity. It was listed on the National Register of Historic Places in 2013.