HMS Malcolm was one of eight Admiralty-type destroyer leaders built for the Royal Navy during World War I. She was the first of only two Royal Navy ships to carry the name Malcolm, although HMS Valkyrie was originally planned to bear the name. She was one of two Admiralty-type leaders to miss the First World War but saw service in, and survived, the Second World War. Her pennant number was changed from D19 to I19 in May 1940. She was broken up in 1945.

HMS Mackay was an Admiralty type, sometimes known as the Scott class, flotilla leader of the British Royal Navy. Mackay was built by Cammell Laird during the First World War, but was completed too late for service then, commissioning in 1919.