Ronald E. Guenther (born October 3, 1945) is a former American football player, coach, and college athletics administrator. He served as the head football coach at North Central College in Naperville, Illinois from 1975 to 1978, compiling a record of 22–12–2. Guenther was the athletic director at the University of Illinois at Urbana–Champaign from 1992 until he retired on July 1, 2011.