Sir John Thayne Forbes (born June 1938) is a retired British judge and barrister. As a High Court judge, he presided over the trial of Harold Shipman who was convicted 2000. Shipman is now recognised as one of the most prolific serial killers in history. He led the Al-Sweady Inquiry, a five-year public enquiry that reported in 2014.
Forbes was born on the Isle of Wight in June 1938. From 1957 to 1960, he studied law at University College London. He graduated with a Bachelor of Laws (LLB) degree and a Master of Laws (LLM) degree.
From 1963 to 1966, Forbes served as an Instructor Lieutenant in the Royal Navy. On 2 December 1966, he was placed on the Emergency List for four years. This marked the end of military service and began the time period during which he was liable for call-up.
Forbes was called to the bar in 1966. In 1984, he was appointed Queen's Counsel (QC). On 13 March 1986, he was appointed a Recorder, a part-time judge.
On 5 June 1990, he was appointed a Circuit Judge. From 1990 to 1993, he was an Official Referee of the Technology and Construction Court. He was elected Bencher of the Inner Temple in 1991. On 24 May 1993, he was appointed a High Court Judge and was assigned to the Queen's Bench Division. He presided over the trial of Harold Shipman, a serial killer who was convicted 2000. Between 2001 and 2004, he was Presiding Judge of the Technology and Construction Court. He retired from the High Court in January 2009.