A grandson of Lord Atkin, Sir Thomas Morison was educated at Winchester College and at Worcester College, Oxford, where he obtained a first class degree in law and was awarded the University’s prestigious Eldon Law Scholarship. Called to the Bar by Gray's Inn in 1960, and became a member of Fountain Court Chambers, where his practice included administrative law and employment law, as well as commercial litigation. He was appointed Queen's Counsel in 1979, and he was a Recorder from 1987 to 1993, when he became a Judge of the Queen's Bench Division. He sat regularly in the Commercial Court from 1996 onwards. He also sat in the Administrative Court and in the Employment Appeal Tribunal, of which he was President from 1996 to 1999. He retired in 2007.

In retirement, Morison served as a local councillor in Wilsthire. His hobbies include reading, gardening, and cooking.

Sir Thomas Morison died in March 2022.