Robert George Goalby (born March 14, 1929) is a former American professional golfer on the PGA Tour, who won the 1968 Masters Tournament, his lone major championship among 11 Tour wins achieved between 1958 and 1971.

Goalby was born, raised, and has lived much of his life in Belleville, Illinois. He attended the University of Illinois, where he played on the football team. He turned professional in 1952. His first Tour win came in 1958, and he won and contended steadily until 1971, when he was 42 years old.

At the 1968 Masters Tournament, Goalby tied Roberto DeVicenzo at the end of 72 holes of regulation play, and would have had to face an 18-hole playoff the next day, had there not been a mistake on DeVicenzo's scorecard. In the final round, DeVicenzo's playing partner Tommy Aaron marked a par-4 on the 17th hole, when DeVicenzo had in fact made a birdie-3. DeVicenzo failed to catch the mistake and signed the scorecard. The rules of golf state that the higher written score signed by a golfer on his card must stand. As such, the error gave Goalby the championship. Goalby, playing in the group behind DeVicenzo, was not personally at fault for anything in the incident. The story received overwhelming attention at the time, and has remained high in public consciousness since. It was recounted in great detail in the 2005 book "The Lost Masters: Grace and Disgrace in '68" by Curt Sampson. The personal relationship between Goalby and DeVicenzo was unaffected by the difficult situation, and the two players formed a partnership years later, for a team event on the Champions Tour.