Jack Crouch, whose given name was John Lionel Crouch, was an English racing jockey. His parents were Walter Thomas Crouch (1877–1959) and Blanche (neé Phillips, 1880–1922), and he was born in 1915 when the family resided in Deptford, part of the Greenwich area of London. In April 1939, Crouch was engaged to Barbara Hives.
Crouch served his apprenticeship at the yard of Stanley Wooton in Epsom. By 1933 he was competing successfully, and by 1936 he had accumulated 31 wins. During October that year it was reported that he was to be retained as the King’s jockey after Joe Childs retired.
In the 1937 Epsom Derby he piloted the horse, Sandsprite, bred by Florence Nagle Florence Nagle, (26 October 1894 – 30 October 1988) was a trainer and breeder of racehorses, a breeder of pedigree dogs, and an active feminist. She successfully challenged the well-established leading gentlemen's clubs of the racing and canine worlds over their gender inequality, and in 1966 became one of the first two women in the United Kingdom licensed to train racehorses.  at odds of 100–1, to second place behind Mid-day Sun, owned by Mrs Lettice Miller, the first woman owner ever to win the Derby.
Crouch died when the de Havilland Dragon Rapide light aircraft he was a passenger in crashed on 20 June 1939. The aircraft had been travelling from Heston to Gosforth Park, where Crouch was due to ride the King’s horse Mouzelle in the Seaton Delaval Stakes; the horse was withdrawn as a mark of respect.