Robert C. Duffy (May 13, 1903 – December 9, 1974) was an American football coach and lawyer. He was the 20th head football coach at Dickinson College in Carlisle, Pennsylvania, serving for two seasons, from 1927 to 1928, and compiling a record of 6–9–1. After serving in World War II, he practiced law in Philadelphia and was elected Register of Wills as a Republican in 1953.