John Edmund Valentine Isaac (14 February 1880 – 9 May 1915), DSO, was an English cricketer: a right-handed batsmen who played ten first-class matches in South Africa and England between 1906 and 1908. He was born at Powick Court, Worcestershire. Isaac's first-class debut came for the South Africa Army cricket team in the only match of that standard they ever played, when they met MCC at Thara Tswane, Pretoria in January 1906.