Graham Clark was born in Lancashire. Director of Physical Education in three schools, took a Masters in Management and was Senior Regional Officer with the Sports Council. He studied singing with Bruce Boyce at the same time and joined Scottish Opera in 1975. He was a Principal at ENO (1978–1985) and has also sung with ROH, Opera North and WNO in the UK.

His extensive career includes 16 seasons / over 100 performances at Bayreuth Festspiele (Loge/Mime Der Ring des Nibelungen, David Die Meistersinger, Steuermann Der fliegende Holländer, Melot/Seaman Tristan und Isolde); 14 seasons at Metropolitan Opera (Loge/Mime, Bégearss The Ghosts of Versailles, Captain Vere Billy Budd, Steva Jenůfa, Herod Salome, Hauptmann Wozzeck, Gregor The Makropoulos Case, Prinz/Marquis Lulu, Tanzmeister Ariadne auf Naxos); over 350 Wagner performances including over 250 performances of Der Ring des Nibelungen.

DVDs include The Ghosts of Versailles (Metropolitan Opera); Die Meistersinger, Der fliegende Holländer, Der Ring des Nibelungen (Bayreuth Festspiele); Der Ring des Nibelungen (Gran Teatre del Liceu; Netherlands Opera); Wozzeck (Deutsche Staatsoper); Ariadne auf Naxos (Opéra National de Paris); Lady Macbeth of Mtsensk (Gran Teatre del Liceu); Witch Hansel & Gretel (WNO).

Nominated for Outstanding Individual Achievement in Opera, including an American Emmy (1983, 1986, 1993); he won a Sir Laurence Olivier Award for Mephistopheles in Busoni's Doktor Faust, 1986; Honorary Doctor of Letters, Loughborough University.