John Hammond was born in Ballincollig, County Cork, Ireland on 9 November 1885, the son of John F B Hammond. He joined the Royal Navy as a Boy Second Class on 30 January 1901. He trained as a Seaman Torpedoman and, by 7 July 1906 he had been rated Leading Seaman and was serving in the Submarine Depot Ship HMS MERCURY. John Hammond next served in the Submarine Depot Ship HMS THAMES until 30 November 1911 when he returned to General Service as a Petty Officer. He qualified as a Torpedo Gunners Mate on 2 December 1912 and was promoted to Warrant Rank on 8 January 1914. On 29 January 1914 he was appointed to the Torpedo Boat Destroyer HMS PORPOISE.

On 16 May 1915 he was appointed to the Submarine Depot Ship HMS FORTH additional for submarine duties. This was followed by an appointment to HMS FORTH ‘for Submarines‘ in November 1915 and ‘for Submarine W1 as First Lieutenant‘ on 1 April 1916. He was promoted to Commissioned Gunner (T) and, on 21 August 1916 he was appointed to HMS C22 as First Lieutenant. On 8 November 1916 was appointed to HMS K4 as Third Hand. K4 was sunk with all hands in the Firth of Forth on the night of 31 January 1918 following a collision with HMS K6. This was another incident in what became known as the Battle of May Island.

John Hammond was the husband of Sarah Elizabeth Hammond of 8, Markland Road, Dover, Kent. He is commemorated on the Portsmouth Naval Memorial on Panel No. 28.