John Tryon was born in Ireland on 18 June 1891, the son of Stephen Tryon and Mary Annie Dickson Tryon of 5, Beaufort Road, Clifton Bristol. He joined the Royal Navy as a Cadet at the RN College, Osborne in May 1904. After time in the Battleship HMS INFLEXIBLE, Sub Lieutenant Tryon joined submarines in June 1913.

Next, as a Lieutenant, in October 1913 he became First Lieutenant of HMS C35 followed, in September 1915, by appointment to E31 as First Lieutenant. His first submarine command was of HMS C12 in June 1916, then, in July 1917, of HMS G8. G8 sailed for patrol on 3 January 1918. The submarine failed to return from that patrol in the North Sea and was lost with all hands from unknown causes on or about 14 January 1918.

John Tryon was the husband of Hilda Irene Tryon of Hallen Lodge, Henbury, Bristol and he is commemorated on the Portsmouth Naval War Memorial on Panel No. 28.