| Birth Date: | 15 April 1979 |
| Birth Place: | Edmonton, Alberta, Canada |
| Ru Position: | Prop |
| Repyears1: | 2004-2006 |
| Repcaps1: | 16 |
Forrest Gainer (born April 15, 1979) is a Canadian rugby player. He plays for Canada national rugby union team. Gainer is 180.3 cm tall (5 ft 11) and weighs 111.8 kg (247 lb).