Robert Edward "Bo" Rein (July 20, 1945 – January 10, 1980) was an American football and baseball player and football coach. He was a two-sport athlete at Ohio State University and served as the head football coach at North Carolina State University from 1976 to 1979, compiling a record of 27–18–1. Following the 1979 season, Rein had assumed the role as head coach at Louisiana State University, but was killed in an aircraft accident in January 1980 before he ever coached a game there.