Robert C. Wagner (born May 16, 1947) is a former American football coach. He was the head football coach at the University of Hawaii from 1988 to 1995 and led the Rainbow Warriors to their first top 20 finish in 1992. Wagner was out of coaching for a few years, but after the 1997 season ended, Wagner agreed to take over the defensive coordinator position for TCU under new coach Dennis Franchione. However, his old mentor Dick Tomey called, asking if he wanted to take over an assistant position on his staff. Wagner gladly accepted and ended up coaching inside linebackers for Arizona.