Colin Boyd, Baron Boyd of Duncansby, is a Scottish judge who has been a Senator of the College of Justice since June 2012. He was Lord Advocate for Scotland from 24 February 2000 until his resignation on 4 October 2006. On 11 April 2006, Downing Street announced that Colin Boyd would take a seat as a crossbench life peer; however, he took the Labour whip after resigning as Lord Advocate. He was formally introduced in the House of Lords on 3 July 2006. On the day SNP leader Alex Salmond was elected First Minister of Scotland, it was reported that Boyd was quitting the Scottish Bar to become a part-time consultant with public law solicitors, Dundas & Wilson. He told the Glasgow Herald, "This is a first. I don't think a Lord Advocate has ever done this—left the Bar and become a solicitor."

His Majesty's Advocate, known as the Lord Advocate, is the principal legal adviser of both the Scottish Government and the Crown in Scotland for civil and criminal matters that fall within the devolved powers of the Scottish Parliament. The Lord Advocate provides legal advice to the government on its responsibilities, policies, legislation and advising on the legal implications of any proposals brought forward by the government. The Lord Advocate is responsible for all legal advice which is given to the Scottish Government.