There is provided a rotation transmission assembly that can be produced in large quantities and at low cost and has an anti-rotation function and an anti-release function. This rotation transmission assembly has a rotation transmission member formed in a substantially circular plate configuration, in a center of which there is a substantially circular cylinder shaped through hole that is formed by an inner circumferential surface, and that includes a rotation transmission portion located on an outer circumferential portion of the rotation transmission member; and an inner side member that is press-inserted into the through hole, wherein the inner circumferential surface of the rotation transmission member is provided with: a smooth ring-shaped surface that is placed adjacent to one end of the inner circumferential surface; and a plurality of protrusion shaped portions that, taking the ring-shaped surface as a basis, protrude inwards in the radial direction, and extend along a portion of the length in the axial direction of the through hole, and wherein the inner side member and the rotation transmission member mesh with each other within the range in which the protrusion shaped portions extend, and are in surface contact with each other within a range in which the ring-shaped surface extends.