HMS R1 was a British R class submarine built at Chatham Dockyard. She was laid down on 4 February 1917 and launched on 25 April 1918 by Lady Sturdee. R1 was commissioned on 14 October 1918. She came too late to see any combat in World War I like most of the other R class submarines. R1 was sold on 20 January 1923 to J. Smith.