Jan Marinus Jongkind (September 19, 1932, Aalsmeer) was a sailor from the Netherlands, who represented his country at the 1964 Summer Olympics in Enoshima.
Jonkind, as crew (Race 1 - 2) on the Dutch Dragon took the 13th place with helmsman Wim van Duyl, fellow crew member Henny Scholtz and Dick Wayboer (Race 3 - 7).
Before his Dragon period Jongkind sailed at a high level in the Flying Dutchman.
From 1968 - 1969 Jongkind sailed the Soling.
Jongkind is one of the first sailmakers who successfully used Dacron as base material for modern racing sails.