Iain Gillies Armstrong, Lord Armstrong (born 26 May 1956) is a Senator of the College of Justice, a judge of the Supreme Courts of Scotland.
Iain Armstrong is a graduate of the University of Glasgow.
Thereafter, he served as a full-time Advocate Depute in the Crown Office until 2003, when he returned to private practice.
He was a member of Scotland's Standing Committee on Legal Education from 1995 until 1999.
From 2009 until 2015 he was a member of the Advisory Panel to the School of Law of the University of Glasgow.