| Jan Plantaz | |
| Fullname: | Johannes Marinus Plantaz |
| Birth Date: | 3 December 1930 |
| Birth Place: | Geldrop, the Netherlands |
| Death Place: | Eindhoven, the Netherlands |
| Show-Medals: | yes |
Johannes "Jan" Marinus Plantaz (3 December 1930 - 10 February 1974) was a road and track cyclist from the Netherlands. He competed at the 1952 Summer Olympics in the road race (individual and team events) and 4 km team pursuit and finished in 22nd, 5th and 8th place, respectively. He won a bronze medal in the road race at the 1951 UCI Road World Championships.
He died from a heart attack during training.