Merlin Hay, 24th Earl of Erroll

Merlin Sereld Victor Gilbert Hay, 24th Earl of Erroll (born 20 April 1948) is a crossbench member of the House of Lords, Chief of the Scottish clan Hay, and hereditary Lord High Constable of Scotland.

Lord Erroll is the son of Sir Iain Moncreiffe of that Ilk and Diana, Countess of Erroll. He was page to the Lord Lyon in 1956. He was educated at Eton College and at Trinity College, Cambridge.

He succeeded his mother, the countess, in 1978 as Earl of Erroll, and in 1985, his father as a Baronet. He is a member of the Council of the Hereditary Peerage Association. As Lord Erroll was Chief of Clan Hay by virtue of his mother's title, his younger brother Peregrine took over their father as Chief of Clan Moncreiffe.

He married Isabelle Jacqueline Laline Astell Hohler (b. Brussels, 22 August 1955), daughter of Major Thomas Sidney Hohler and heiress to the family of Astell, of Everton House, Bedfordshire, in 1982. The Countess is a patroness of the Royal Caledonian Balland served as High Sheriff of Bedfordshire in 2015.

The couple has two sons and two daughters:

• Harry Thomas William Hay, Lord Hay (b. Basingstoke, 8 August 1984), engaged to Clementine Travis
• Lady Amelia Diana Jacqueline Hay (b. Basingstoke, 23 November 1986)
• Lady Laline Lucy Clementine Hay (b. Basingstoke, 21 December 1987)
• Hon. Richard Merlin Iain Hay (b. Basingstoke, 14 December 1990); took the surname of Astell by Royal Licence in 2015.

The Earl of Erroll has been a lieutenant at the Atholl Highlanders since 1974, and is a Member of the Royal Company of Archers. He served in the 21st SAS Artists Rifles (V) Territorial Army from 1975 to 1990, and was an Honorary Colonel of the Royal Military Police (Territorial Army) from 1992 to 1997.

Erroll has worked as a marketing and computer consultant, is a Freeman of the City of London and a Member of the Court of Assistants of the Worshipful Company of Fishmongers, of which he was Prime Warden in 2000–2001. He continues to head the club, Puffin's Club, founded by his father. He is also President of ERADAR the Chamber for Electronic Business, and Chairman of the Digital Policy Alliance (EURIM).

He is a director of Lasseo, a not-for-profit technical standardization and interoperability membership organisation for smartcard technologies.

Lord Erroll was one of 90 excepted hereditary peers elected to remain in the House of Lords following the House of Lords Act 1999. A programmer and system designer by trade he sits as a crossbencher and usually speaks on matters relating to cybersecurity and information technology. He was a member of the Science and Technology Committee and criticised Tony Blair's government for the failure to curb cyber crime after various government agencies, including the Ministry of Defence and HM Revenue and Customs, reported massive losses of data in 2008. Most recently he was a member of the Information Committee from 2007 to 2012.

• Leigh Rayment's Peerage Pages
• Leigh Rayment's list of baronets