A twist-lock connector assembly for securing an engaged electrical plug to an electrical outlet which includes a rotatable cylindrical sleeve disposed enclosing an electrical plug and a modified cover plate for replacing the conventional cover plate of an electrical outlet, such as a wall socket or a portable power box. The prong end of the sleeve includes a plurality of radially inwardly projecting nubs provided along an inner cylindrical surface thereof. The cover plate includes an upstanding cylindrical wall disposed about a periphery of each socket access opening. A plurality of thread members are formed on the exterior surface of each upstanding cylindrical wall and which are designed to matingly engage the nubs on the inner cylindrical surface of the sleeve as the sleeve is twist-rotated over the upstanding cylindrical wall. In use, the electrical plug is inserted into the socket portion of the wall outlet and the cylindrical sleeve is rotated about a 1/4 turn. This causes the inner disposed nubs of the sleeve to lockingly engage the outer disposed threads of the upstanding cylindrical wall of the cover plate. The electrical plug is prevented from being accidentally pulled loose from the outlet by its connection with the second sleeve end of the cylindrical sleeve.