A workpiece conveyor system comprising: a conveyance apparatus which conveys workpieces in one direction, a stopper which is mounted on the conveyance apparatus so as to stop workpieces which are conveyed by the conveyance apparatus at a predetermined position, and a takeout apparatus which takes out workpieces which have been stopped by the stopper from the conveyance apparatus. An outer edge of the stopper in an opposite direction to a conveyance direction of workpieces extends in a curved shape in a transverse direction of the conveyance apparatus.