| Position: | Defence |
| Shoots: | Left |
| Height Ft: | 6 |
| Height In: | 0 |
| Weight Lb: | 185 |
| Played For: | New England Whalers |
| Birth Date: | December 7, 1952 |
| Birth Place: | Southampton, Ontario, Canada |
| Draft: | 79th overall |
| Draft Year: | 1972 |
| Draft Team: | New York Rangers |
| Career Start: | 1972 |
| Career End: | 1977 |
John Martin "Marty" Gateman (born December 7, 1952, in Southampton, Ontario) is a Canadian retired ice hockey defenceman.
Gateman played junior hockey for the Hamilton Red Wings in the Ontario Hockey Association. He was drafted 79th overall by the New York Rangers in the 1972 NHL Amateur Draft but never played in the National Hockey League. Gateman turned pro in 1972 with the Central Hockey League's Omaha Knights. He then spent three years in the American Hockey League with the Providence Reds. He moved to the Cape Codders of the North American Hockey League before playing 12 games for the New England Whalers of the World Hockey Association and then returning to the NAHL with the Binghamton Dusters. Gateman spent one final year in the International Hockey League with the Fort Wayne Komets and back in the American Hockey League with the Rhode Island Reds before retiring in 1977.