HMS H29 was a British H class submarine built by Vickers Limited, Barrow-in-Furness. She was laid down on 19 March 1917 and was commissioned on 14 September 1918. HMS H29 was sunk during trials at Devonport Dockyard following a recent refit on 9 August 1926. Five civilians and one crewman died. H29 was raised and sold in Pembroke Dock on the 7 October 1927.