Lieutenant William John ("Jack") Van de Kasteele was an English officer of the Royal Navy who died during the Second World War.
He was born in 1913, in Devonport, the son of Willem Leonard, a Dutch-born timber merchant and later honorary Consul of the Netherlands at Plymouth, and Gertrude Van de Kasteele (née James). Van de Kasteele completed his passing out from the Royal Naval College, Dartmouth, in 1930, upon which he joined the battleship Nelson for a period of three years.
After taking his courses for promotion to lieutenant, in which he achieved five "firsts", he transferred to the battleship Queen Elizabeth, flagship of the Mediterranean Fleet. He later served aboard the destroyers Viscount and Grenade, and joined HMS Excellent in 1938 for specialist gunnery training.
Aged 28, Van de Kasteele died on 13 October 1941, in an explosion, while assigned to the heavy cruiser Norfolk.
Van de Kasteele, who married Margaret Bennett, is buried in Lyness Royal Naval Cemetery, Scapa Flow.
- Van De Kasteele, William John, cwgc.org. Retrieved 18 March 2014.