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.

[11] Lord Erroll has worked as a marketing and computer consultant,[2] is a Freeman of the City of London,[2] and Prime Warden of the Worshipful Company of Fishmongers (2000–01).

[15] He was a director of LASSeO, a not-for-profit technical standardization and interoperability membership organisation for smartcard technologies.

[17] A programmer and system designer by trade,[18] 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 Gordon Brown's government for what he said was a failure to curb cybercrime after four government agencies, including the Ministry of Defence and HM Revenue and Customs, reported massive losses of data in 2008.