The Denny Baronetcy, of Castle Moyle in the County of Kerry, was created in the Baronetage of Ireland on 12 January 1782 for Barry Denny. He was a descendant of Sir Anthony Denny, confidant of King Henry VIII. The second Baronet was about to be raised to the peerage when he was killed in a duel in 1794. The third and fourth Baronets represented Tralee in the House of Commons. The sixth Baronet was a founder of the North-West Mounted Police in Canada, Indian agent and author.
There is no such place as Castle Moyle. This was an error in the letters patent creating the baronetcy. The patent was meant to be referring to the family seat of Castle More in County Kerry. The Denny Earls of Norwich were members of another branch of the family.
The Denny Baronetcy, of Dumbarton in the County of Dunbarton, was created in the Baronetage of the United Kingdom on 16 June 1913 for the naval architect and shipbuilder Archibald Denny. He was a Director of William Denny & Brothers Ltd, shipbuilders and engineers, of Dumbarton. The second Baronet was President of William Denny & Brothers Ltd. The third Baronet was Chairman of the Air Registration Board.