A rotation transmission disc includes: an outer circumferential portion on which a load acts when rotation is transmitted; a center opening portion formed inside the outer circumferential portion; and a plurality of attachment holes for attachment of the rotation transmission disc 1 to a rotating element. A first crosspiece portions are formed in each of ranges of divided angles formed by two adjacent attachment holes with respect to a center of the rotation transmission disc. The first crosspiece portion extends from a load point, which is an intersection between a straight line extending in a radial direction to internally divide the divided angles at a predetermined angular ratio and a load radius position of the outer circumferential portion, to one of the attachment holes forming the divided angles. The second crosspiece portion extends from the load point to the other attachment hole of the attachment holes forming the divided angles.