Walter Ian Reid Fraser, Baron Fraser of Tullybelton, PC (3 February 1911 – 17 February 1989) was a British judge.
Fraser was made a Privy Counsellor in 1974. One year later he was appointed as a Lord of Appeal in Ordinary, and as a Law lord he was subsequently created a life peer. He took the title Baron Fraser of Tullybelton, of Bankfoot in the County of Perthshire.
Ian Fraser was born in Glasgow on 3 February 1911, the only child of Alexander Reid Fraser and his wife Margaret Russell MacFarlane. He was educated at Repton School and later studied Philosophy, Politics and Economics at Balliol College, Oxford, graduating in 1932 with First Class Honours. He finished his studies at the University of Glasgow with a Bachelor of Laws in 1935. The following year he was admitted to the Scottish Faculty of Advocates, where he soon earned a reputation as an excellent jurist. At the same time he held a teaching post at the University of Glasgow and from 1948 at the University of Edinburgh. His 1936 work "Outline of Constitutional Law" (2nd edition 1948) was soon regarded as the standard work on British constitutional law.
During the war he served first as a sergeant in an anti-aircraft battery of the Territorial Army. Later he transferred to the Royal Artillery, was promoted to the rank of major and served in the theatre of war in Burma. In 1945 he was appointed Advocate Depute and eventually rose to be the Home Depute in the Crown Office. In 1953 he was appointed QC. In 1954 he served on the Scottish Law Reform Committee and from 1960 to 1962 on the Royal Commission on the Police. From 1959 to 1964 he served as Dean of the Faculty of Advocates. From 1964 to 1974, he was a Senator of the College of Justice and had the courtesy title of Lord Fraser. In 1974 he was appointed to the Privy Council, and on 13 January 1975 was created a life peer with the title Baron Fraser of Tullybelton, of Bankfoot in the County of Perth, and took the office of Lord of Appeal in Ordinary.