In British horse racing, it is very common for many members of the same family to be participants in the sport, often through many generations. Children often take over racing stables from their parents, and often ride for their parents when first starting out. For periods, certain families have become highly prominent and it can sometimes be difficult in the historical record to distinguish particular individuals when names are shared. This is a list of male line families (i.e. those families that share a surname) of which at least three members have gained some notability in horse racing in Great Britain.
Arnull
Sam Arnull, jockey; younger brother of John Arnull, jockey; father of Bill Arnull, jockey
Balding
Gerald Barnard Balding, Sr., father of Toby Balding Ian Balding, father of Clare Balding Andrew Balding
Cannon Tom Cannon, Sr., father of Kempton Cannon Mornington Cannon Tom Cannon, Jr. Charles Cannon
Carson
Willie Carson, and descendants
Chifney
Samuel Chifney, Sr. (1753-1807), jockey; father of William Chifney, trainer, Samuel Chifney, Jr. (b. 1786), jockey
Childs John Childs, jockey; father of Albert Childs, jockey Arthur Childs, jockey Charlie Childs, jockey Henry Childs, jockey Joe Childs, jockey
Day John Day, trainer, father of John Barham Day (1793-1860), jockey and trainer, father of Sam Day, Jr. (1818-1838), jockey John Day, Jr. (1819-1883), jockey and trainer, grandfather of Mornington, Kempton, Tom Jr. and Charles Cannon; great-grandfather of Keith Piggott William Day (1823-1908), trainer, father of Alfred Day, founder of Fontwell Racecourse Alfred Day (1830-1868), jockey Sam Day (1801-1866), jockey
Goodisson Dick Goodisson (c. 1750-1817), Oaks-winning jockey; father of Tom Goodisson (1782-1840), multiple Classic-winning jockey Charles Goodisson (c. 1786-1813), jockey
Greaves David Greaves, jockey Valerie Greaves (1945-2015), jockey, mother of Alex Greaves (b.1968), jockey, trainer
Hannon Harry Hannon, trainer; father of Richard Hannon Sr. (born 1945), four times British flat racing Champion Trainer; father of Richard Hannon Jr. (born 1975), trainer
Hastings Aubrey Hastings, trainer; father of Peter Hastings-Bass (1920-1964), trainer; grandfather of Andrew Balding and Clare Balding; father of William Hastings-Bass, 17th Earl of Huntingdon (born 1948), trainer
Hills Barry Hills, trainer; father of Michael Hills, jockey Richard Hills, jockey Charlie Hills, trainer John Hills, trainer
Moore George Moore, trainer; father of Gary Moore, trainer; father of Ryan Moore, jockey Jamie Moore, jockey Joshua Moore, jockey
Piggott Ernest Piggott, father of Keith Piggott, father of Lester Piggott
Scudamore Michael Scudamore, father of Peter Scudamore, eight time British jump racing Champion Jockey; partner of Lucinda Russell, and father of Michael Scudamore, Jr., trainer Tom Scudamore, jockey
Singleton John Singleton the Elder, (1715-c.1795), first rider to Lord Rockingham between 1760 and 1780; uncle of John Singleton the Younger, also rider to Lord Rockingham and winner of the first running of the St. Leger Stakes in 1776; father of John Singleton, Jr., who rode the winner of the 1797 Derby
Templeman Sim Templeman (1805-1884), winner of seven Classics; uncle of William Templeman (1858-1914), jockey, father of Clark Templeman (1885-1953), jockey Arthur Templeman (1886-1938), jockey, winner of the 1905 Cambridgeshire Handicap Fred Templeman (1892-1973), jockey, winner of the 1919 Derby
Tinkler Colin Tinkler Sr (1927-2016), trainer, father of Colin Tinkler Jr (b 1954), jockey and trainer, father of Andrew Tinkler (b 1985), jockey Nicky Tinkler, amateur jockey Nigel Tinkler (b 1958), jockey and trainer
Wragg Harry Wragg (1902-1985), Classic winner as jockey and trainer, brother of Sam Wragg (1909-1983), Classic winning jockey, brother of Arthur Wragg (1912-1954)