Geoffrey Alan Blyth (27 July 1929, London – 14 August 2007, Lavenham) was an English music critic, author, and musicologist who was particularly known for his writings within the field of opera. He graduated from the Rugby School before attending the University of Oxford where he studied with Jack Westrup. During the early 1960s he began writing music criticism for The Times and later in The Listener, The Guardian, and Gramophone. He was an associate editor for the magazine Opera between 1967 and 1983, and worked as a staff critic for The Daily Telegraph between 1977 and 1989. A prolific writer, Blyth edited discographic reviews of opera and song, several entries in the Grove Dictionary of Music and Musicians, and wrote the books Wagner’s Ring: an Introduction (London, 1980) and Remembering Britten (London, 1981) among other publications.