A toner container detachably mountable to an image forming apparatus, includes a container body for containing toner; and a sealing member. The sealing member includes a sealing portion and a coupling portion. The coupling portion includes a supporting portion provided on the sealing portion and an engaging portion provided at a free end of the supporting portion. The engaging portion includes a rotational force receiving portion and a locking portion. The rotational force receiving portion is capable of being abutted in a circumferential direction of a hollow cylindrical driving member of the image forming apparatus. The locking portion is capable of being abutted in an axial direction of the hollow cylindrical driving member to prevent the sealing member from moving in the axial direction of the container body when the container body moves away from the hollow cylindrical driving member.