Etherton attended St Paul's School and then studied history and law at Corpus Christi College, Cambridge. He was in the British Sabre team from 1977 to 1980 and qualified for the Moscow Olympics.
Etherton was called to the bar in 1974 and became a QC in 1990. He was appointed a High Court judge in 2001 and assigned to the Chancery Division, receiving the customary knighthood. In August 2006, he was appointed Chairman of the Law Commission, the statutory independent body created by the Law Commissions Act 1965 to keep the law under review and to recommend reform where needed.
In June 2022 it was announced he would lead a review into the impact of a historical ban on LGBT people serving in the armed forces.The review will apply to veterans who served between 1967, when homosexual acts began to be decriminalised, and 2000 .
Etherton is openly gay, and celebrated his civil partnership in 2006. On his appointment as Lord Justice of Appeal in 2008, he said, "My appointment also shows that diversity in sexuality is not a bar to preferment up to the highest levels of the judiciary".
- London Gazette issue 56092 Page 535,16 January 2001
- http://www.legalday.com/commentaries/dca/chair_law_commission.html "Terence Etherton to Chair Law Commission" legalday.com 25 July 2006
- London Gazette issue 58845 page 15299 7 October 2008
- http://www.judiciary.gov.uk/media/media-releases/2012/number-10-press-release-chancellor-high-crt-20122012 "Appointment of Chancellor of High Court" Judicial Office 20 December 2012
- https://www.bbc.co.uk/news/uk-61882562 (accessed 16 July 2023)
- http://business.timesonline.co.uk/tol/business/law/article3758071.ece "Sir Terence Etherton, Chairman of the Law Commission" The Times 21 April 2008}
- http://www.pinknews.co.uk/2008/09/22/out-gay-man-becomes-lord-justice-of-appeal/ "Out gay man becomes Lord of Appeal" Pink News 22 September 2008