An adapter (14) allows direct connection of a handheld spray device (10) to paint cans (12, 12A, 12B, 12C), of varying dimensions. The adapter (14) includes a cage (60) for holding the paint can (12, 12A, 12B, 12C), a cap (62) that connects the cage (60) to the handheld spray device (10), and a gasket (64) that seals the open upper end of the paint can (12, 12A, 12B, 12C) to the cap (62). The adapter (14) may also include a suction tube extension 66 that is connectable between the pump inlet (52) and the suction tube (54) of the spray device (10).