Abstract: A carton loader for automatically loading stacks of cartons onto a mass feeder for supplying cartons to a packaging machine includes a loader in which stacks of cartons are received and held, and a carriage on which the loader is pivotally mounted. After the stacks of cartons are received, the loader is pivoted from a loading position to a stacking position. The carriage is then moved along the mass feeder for the packaging machine toward a magazine or supply of previously stacked cartons, whereupon the stack of cartons within the loader is moved in engagement and stacked against the previously loaded cartons.