John Edmund Valentine Isaac (14 February 1880 – 9 May 1915), DSO, was an English first-class cricketer: a right-handed batsmen who played ten matches in South Africa and England between 1906 and 1908. He was born at , Worcestershire. In he played four times for Orange Free State in the Currie Cup, though his highest score was only 34 not out. Curiously, in Isaac's eight visits to the crease he was four times out bowled to a man who would take six or more wickets in that innings (JJ Kotze 8-57, RO Schwarz 7-25, AEE Vogler 6-34 & 8-24).