HMS H1

HMS H1 was a British H-class submarine built by Canadian Vickers Co., Montreal. She was laid down on 11 January 1915 and was commissioned on 26 May 1915.

H1 crossed the Atlantic from St John's, Newfoundland to Gibraltar escorted by the armed merchant cruiser HMS Calgarian (1913). She was accompanied by HMS H2, HMS H3 and HMS H4.

H1 mistakenly sank ITALIAN SUBMARINE H5 off Cattaro on 15 April 1918.

H1 was sold on 7 March 1921 in Malta.