HMS H33
 HMS H33 was a British H class submarine built by Cammell Laird Birkenhead. She was laid down on 20 November 1917 and commissioned on 17 May 1919.In March 1937 the submarine navigated the Gloucester and Sharpness Canal in the company of H49 whose commander had arranged the trip. HMS H33 was scrapped at Troon on 19 May 1944.