private, coeducational institution of higher learning in Troy, New York, U.S. It includes schools of architecture, engineering, humanities and social sciences, management and technology, and science. In addition to undergraduate studies, all five schools offer master's degree programs and four offer doctorates. There is also a graduate centre in Hartford, Connecticut. Research Facilities include Rensselaer Technology Park, Darrin Communications Center, and the George M. Low Center for Industrial Innovation. The Darrin Fresh Water Institute is located in the Adirondack Mountains. Total enrollment is approximately 6,600.

The institute was founded in 1824 by Stephen Van Rensselaer and Amos Eaton; Eaton, its senior professor, was a pioneer of American scientific research and education. Rensselaer was one of the first colleges in the United States specifically dedicated to the study of science and civil engineering.