William Metcalfe was born on 4 February 1895, the son of Mr and Mrs C Percival Metcalfe of Netley Abbey, Hampshire. He joined the Royal Navy as a Cadet at the Royal Naval College Osborne on the Isle of Wight on 15 January 1908. He was promoted to Midshipman on 15 September 1912 and appointed to the battleship HMS HERCULES on the same date. On 7 March 1913 he was appointed to the battleship HMS KING GEORGE V and promotion to Sub Lieutenant followed on 15 September 1914. On 11 May 1915 he joined the Grand Fleet flagship HMS IRON DUKE for the Torpedo Boat Destroyer HMS OAK.

His submarine career began on 5 June 1916 when he was appointed to HMS DOLPHIN ‘for Submarine Training’ and, on 1 September 1916, he was appointed to HMS D8 as First Lieutenant. He was promoted to Lieutenant on 15 November 1916.

On 26 January 1917 he was appointed to HMS E50 as First Lieutenant. E50 was lost with all hands in the North Sea on 1 February 1918. It is believed that the submarine hit a mine.

William Metcalfe is commemorated on the Portsmouth Naval Memorial on Panel No. 28.