HMS C17 was a C-class submarine built by HM Dockyard, Chatham for the Royal Navy. She was laid down on 11 March 1907 and was commissioned on 13 May 1909. C17 collided with C16 in the North Sea, south of Cromer, Norfolk on 14 July 1909, and with destroyer Lurcher in May 1917. C17 was sold on 20 November 1919.