Bruce was born in Edinburgh, Scotland. He is the second son of Andrew Bruce, 11th Earl of Elgin, and Victoria Usher. He was educated at Glenalmond College. Bruce went up to Balliol College, and whilst studying at the University of Oxford, he was elected as the President of the Oxford Union in 1989.
Formerly a solicitor in Edinburgh, Bruce now works in the environmental power industry, having been UK chief executive of Airtricity and the Chairman of the British Wind Energy Association, now RenewableUK. He is currently global head of corporate affairs at Mainstream Renewable Power, and from 2009-2015 was a director of the Friends of the Supergrid. In October 2012 he was appointed chairman of the UK Government's Offshore Wind Programme Board. He sat on the steering committee of Norstec, the global offshore wind industry network.
In 2008 Bruce was appointed an officer of arms at the Lyon Court as Unicorn Pursuivant. In April 2012 he was promoted to the position of Marchmont Herald. He was previously Finlaggan Pursuivant (private officer of arms to the Clan Donald), in which role he was installed in 2005 by Godfrey Lord MacDonald. This marked a reinstatement of the traditional MacDonald heraldic role after a break of 510 years.
On 17 May 2003, he married Donna Maria Sofia Giovanna Rosa Granito Pignatelli di Belmonte, a younger daughter of the Prince of Belmonte. They live in Edinburgh, and have two children.
- Macalister, Terry (30 May 2008). "Energy boss with the wind in his sails". The Guardian. Retrieved 19 June 2016.
- Cracroft's Peerage
- Mainstream website
- Friends of the Supergrid
- DECC Offshore Wind Programme Board announcement October 2012 Archived October 23, 2012, at the Wayback Machine.
- Norstec launch event October 2012
-  Installation of Clan Donald Officer of Arms by Gordon Casely
- Cochrane, capitan de mar y guerra