William R. Greiner (June 9, 1934 – December 19, 2009) was President of the University at Buffalo (UB) in the State University of New York (SUNY) system from 1991 to 2004, where he worked for 42 years. Prior to becoming President, Greiner served in other capacities in the University at Buffalo Law School, and in UB's administration. He was educated at both Yale University and Wesleyan University, earning degrees in economics and law, including a doctorate in law from Yale. Under Greiner's leadership, research, educational, sports, arts, and student living complexes were constructed. Greiner co-wrote two books. He retired from UB in 2009, and died shortly thereafter due to heart surgery complications.