Stephen Wheeler Downey (July 25, 1839 – August 3, 1902) was a lawyer and politician in Wyoming. A Union Army veteran of the American Civil War, he was an early white settler of Wyoming, and served as its treasurer, auditor, and delegate to Congress. After statehood, Downey continued to serve in local and state office, including Speaker of the Wyoming House of Representatives. Downey was a founder of the University of Wyoming, and the longtime president of its board of trustees.