Abstract: A roll-on dispenser comprises a generally tubular barrel having an open forward end and a generally tubular ball-carrying member having an open rear end which is slidably received in the chamber of the barrel. The ball-carrying member has a ball applicator rollably mounted in its forward end. The rear end of the barrel is vented to the atmosphere, and a one-way follower device is slidably disposed in the barrel chamber for forward sliding movement. A cap is adapted to be threaded on the ball-carrying member and, when screwed thereon, pulls the ball-carrying member forwardly in the barrel chamber to increase the effective volume of the chamber and create a partial vacuum or sub-atmospheric pressure therein, whereupon the atmospheric pressure in the rear end of the barrel chamber will force the one-way follower forwardly by a distance corresponding to the volume of fluent material previously dispensed.