A member of a famous sporting family, Jack Green excelled as an amateur boxer and rugby footballer before five years service in World War II. In 1947, he was granted a NSW trainer's permit, and began to make his name with a small team of horses, including problem horses such as Silent, Conductor and Winmil, which he restored to winning form.
Green's career received a huge boost through his association with the progeny of Star Kingdom. The sire's first two winners, Kingster (AJC Breeders' Plate) and Ultrablue (AJC Gimcrack Stakes), were both trained by Green, and there was rarely a time when there was not a son or daughter of Star Kingdom in his charge. Among his stable stars were the full brothers Sky High and Skyline, who were bred and raced by AJC Chairman Sir Brian Crowley. Sky High raced for five seasons and won 29 races including the Golden Slipper Stakes, Victoria Derby, Lightning Stakes (twice), Futurity Stakes, Mackinnon Stakes, Caulfield Stakes (twice), AJC All-Aged Stakes and Epsom Handicap. Skyline won four races including the Golden Slipper Stakes, the AJC Derby and the STC Hill Stakes. Other progeny of Star Kingdom to excel under Green's training were Starover and Gold Stakes.
Green's greatest training feat was the victory of Baystone in the 1958 Melbourne Cup. He had bought Baystone in 1954 as a yearling and patiently developed him into a strong two mile performer.
Although Green never won the Sydney trainers' premiership, he was four times second to Tommy Smith, and had some 80 feature race wins to his credit.
Green was inducted into the Hall of Fame in 2009.