Jean-François "J.F." Jenny-Clark (12 July 1944 in Toulouse, France – 6 October 1998 in Paris) was a French double bass player who appeared, estimated as one of the most important bass players of European jazz.

Together with drummer Aldo Romano he provided the rhythm section for Don Cherry's European quintet of 1965, recorded with Steve Lacy and performed concerts with Keith Jarrett (around 1970) and for Jasper van 't Hof's group Pork Pie (with Charlie Mariano) (around 1975).