A solid ink stick supply system and related method for delivering solid ink sticks to an ink jet print head reservoir is disclosed. The supply system includes a housing with a keyed plate that guides the ink sticks into the proper loading position in a supply channel. A pusher rod in the supply channel transfers an ink stick onto an endless belt for delivery to the print head reservoir. A push device on the endless belt engages and delivers the ink stick to the print head reservoir. A second ink stick is transferred from the supply channel to the endless belt and is retained on the belt by a stop device. A method for efficiently loading ink sticks into the supply system is also provided.