Iain Armstrong, Lord Armstrong is a Senator of the College of Justice, a judge of the Supreme Courts of Scotland.
Armstrong was admitted to the Faculty of Advocates in 1986. His pupillage was with Duncan Menzies and Donald Findlay. Armstrong was appointed a Queen's Counsel in 2000. From 1998 to 2000, he served as standing junior counsel for the Department of Social Security, predominantly handling appeals to the Social Security Commissioners and to Court of Session. Thereafter, he served as a full-time Advocate Depute in the Crown Office until 2003, when he returned to private practice. He was appointed Vice-Dean of the Faculty of Advocates in 2008. On 15 February 2013, Armstrong was appointed a Senator of the College of Justice.