The son of Sir Hugh Griffiths, he was educated at Charterhouse School and St John's College, Cambridge.

During the Second World War he served in the Welsh Guards, receiving a Military Cross in 1944 for an action in which he disarmed a German tank.

In 1971, Griffiths was knighted[2] and was made Judge of the High Court of Justice, Queen's Bench Division, a post he held until 1980.

At Cambridge University, he won Blues for cricket in 1946, 1947, and 1948, recording career-best figures of 6 for 129 against Lancashire in 1946.

He also made eight appearances in the County Championship for Glamorgan, taking 4 for 61 against Surrey on his debut in 1946.