The present invention relates to a toner cartridge and an image forming apparatus comprising such a cartridge. This cartridge comprises a casing including an accommodation chamber accommodating toner and a discharge opening capable of discharging the toner; a pump configured to discharge the toner through the discharge opening by using air; and a coupling member configured to receive a rotational force for driving the pump, wherein as viewed along an axis of the coupling member in a state that the toner cartridge takes an attitude in which the discharge opening directed downward, the discharge opening is on a first side with respect to a center of the pump in a horizontal direction, and an axis of the coupling member is on a second side which is opposite from the first side, with respect to the center of the pump in the horizontal direction.