John Mervyn Guthrie Griffith-Jones, CBE MC (1 July 1909 – 13 July 1979) was a British judge and former barrister. He is most famous for leading the prosecution of Penguin Books in the obscenity trial in 1960 following the publication of D. H. Lawrence's Lady Chatterley's Lover. His much quoted remark in his opening statement as to whether the novel was something "you would even wish your wife or servants to read" is often cited as representing the extent to which the British 'Establishment' had fallen out of touch with popular opinion at the time. He failed to convince the jury at the Chatterley trial, and the publishers were acquitted.
Griffith-Jones was born in Hampstead, London. His father, John Stanley Phillips Griffith-Jones (1877/8–1949), was also a barrister. He was educated at Eton College and Trinity Hall, Cambridge, and was called to the Bar at Middle Temple in 1932, specialising in criminal law. He served with the Coldstream Guards during the Second World War, and was awarded the Military Cross in 1943. After the war, he was one of the British prosecuting counsel at the Nuremberg Trials (as Junior Counsel).
He returned to the bar when he left the Army in October 1946 and became a specialist prosecuting counsel. He was counsel for the Crown at the north London quarter sessions from 1946 to 1950, and then at the Central Criminal Court at the Old Bailey from 1950 to 1964. He became senior Treasury counsel in 1959, and became a founder member of the Criminal Law Revision Committee that year.