Marvin M. "Vinny" Giles III (born January 4, 1943) is an American amateur golfer. He is best known for winning both the U.S. Amateur and the British Amateur.
Giles finished second in the U.S. Amateur three straight years, 1967 to 1969, before finally winning in 1972. This was in the stroke play era. His victory in the British Amateur came in 1975. He won numerous other amateur tournaments, including seven Virginia State Amateurs, as well as three Virginia Open titles.
Giles played on four Walker Cup teams (1969, 1971, 1973, 1975), winning three times, and captained the 1993 team to victory. He also played on three winning Eisenhower Trophy teams (1968, 1970, 1972) and captained the 1992 team to a runner-up finish.
Giles served on the Executive Committee of the Virginia State Golf Association for over 20 years, and then was first an Associate Director and then a Director of the Southern Golf Association for three years.