Lord Clarke went to Oakham School, followed by King's College, Cambridge, where he studied economics before switching to law. He was called to the Bar by Middle Temple in 1965. He practised Admiralty and commercial law as a member of 2 Essex Court (now Quadrant Chambers), latterly as Head of Chambers. He was appointed Queen's Counsel in 1979, and he was a Recorder from 1985 to 1992. He also sat as an Admiralty and commercial arbitrator. In 1993, he was appointed to the Queen's Bench Division, made Admiralty Judge, and nominated to sit in the Commercial Court. He was appointed to the ancient post of Admiralty Judge of the Cinque Ports in 1997. He was a Lord Justice of Appeal from 1998 to 2005, when he was made Master of the Rolls. In 2009, he was created a life peer and appointed as one of the first intake of Justices of the Supreme Court of the United Kingdom. He retired in 2017.

Lord Clarke enjoys bridge, golf, and tennis.