John Torrey (August 15, 1796 – March 10, 1873) was an American botanist, chemist, and physician. Throughout much of his career, Torrey was a teacher of chemistry, often at multiple universities, while at the same time pursuing botanical work. Dr. Torrey's botanical career focused on the flora of North America. His most renowned works include studies of the New York flora, the Mexican Boundary, the Pacific railroad surveys, as well as the uncompleted Flora of North America.