Abstract: A composite seal ring intended to be compressed between two surfaces which are to be applied against each other in a sealed manner, wherein the composite seal ring comprises firstly a metal seal ring comprising a core constituted by a spiral spring surrounded by a metal sheath which provides two peripheral lips projecting outwardly substantially in the mid-plane of the said metal seal ring, and secondly by a toroidal elastomer seal which surrounds the said metal seal ring, together with members for connecting the toroidal elastomer seal to the metal seal ring, said members being freely lodged between the projecting lips of the said metal seal ring and being rigidly lodged in a corresponding slot of the said toroidal elastomer seal.