A ventilated vehicle seat includes a vent panel underlying an air permeable trim cover. The vent panel includes a vent that is closed to block air flow when the seat is unoccupied and open to permit air flow when an occupant is on the seat. Opening and closing of the vent is actuated by the weight of the seat occupant. Multiple openings can be spaced along the vent so that forced air flows primarily through vent openings directly alongside the legs or torso of the seat occupant. An effective passive vent panel can be easily made from a sheet of polymeric material with a series of elongated slits cut through the sheet.