The ring seal and retainer assembly includes an annularly shaped ring seal defining a radial inner surface, a radial outer surface, first and second axial end surfaces and a central bore for fluid or gas passage. A retainer is provided for affixing and positioning a ring seal in a sealing assembly. The retainer includes a circular sidewall sized and positioned to engage and cover the ring seal's radial outer surface. The retainer includes an arcuate flange which extends at one of the retainer's axial extremities to form a concave interior and a convex exterior. Preferably, the arcuate flange extends outwardly to increase the retainer's radius and the arcuate flange is sized to compressibly engage the interior sidewall of the component block's counterbore.