Dr. Stephen D. H. Hsu (born 1966) is professor of theoretical physics at the University of Oregon. He received a Ph.D. from the University of California, Berkeley in 1991 and B.S. from the California Institute of Technology in 1986. He was a Harvard Junior Fellow and assistant professor at Yale University before moving to the University of Oregon in 1998.
He is a co-founder of SafeWeb, which was acquired by Symantec on October 15, 2003. In 2005 Stephen, along with SafeWeb co-founder James Hormuzdiar, co-founded RobotGenius, an Oakland based security software company.