A toner supply container includes a toner container body including a cylindrical portion and an opening, and a sealing member provided at one axial end portion of the container body. The sealing member is movable relative to the container body in an axial direction and includes a sealing portion provided at a side adjacent the container body and a coupling portion provided at a side remote from the container body. The coupling portion includes a supporting portion provided on the sealing portion, an engaging portion provided at a free end of the supporting portion, and a displacing force receiving portion provided on the supporting portion at a position closer to the container body than the engaging portion. The displacing force receiving portion is displaceable with the supporting portion and has a radially outermost part that is more remote from a rotation axis of the container body than a radially outermost part of the engaging portion. The supporting portion, the engaging portion, and the displacing force receiving portion are made of a plastic material.