A toner supply container is detachably mountable to an image forming apparatus. The container includes a toner accommodating portion to accommodate toner and has a supply opening to supply toner into the image forming apparatus, a feeding member to feed the toner in the toner accommodating portion toward the supply opening, and a sealing member to seal the supply opening. The sealing member has a locking portion to be locked by a locking member provided in a main assembly of the apparatus, and a coupling portion to be coupled with a drive coupling member provided in the main assembly. The sealing member is rotatable integrally with the feeding member by a rotational force received by the coupling portion from the drive coupling member. The locking portion and the coupling portion are spaced apart from each other with respect to a mounting direction of the container.