Gaily
- Gaily (horse) – 1865: Lincoln Handicap
- Gaily (horse sired by Sir Gaylord) – 1974: Irish 1,000 Guineas
Galantine
- Galantine (horse) – b. 1828
- Galantine (horse sired by Gallinule) – 1904: Cheveley Park Stakes
Galileo
- Galileo (horse) – b. 1998
- Galileo (horse sired by Jape) – 2002: Neptune Investment Management Novices' Hurdle
Gallant Knight
- Gallant Knight – 1930–32: Dixie Stakes, Latonia Derby
- Gallant Knight (horse sired by Prince Chevalier) – 1960–61: Dante Stakes, Horris Hill Stakes
Galopade
- Galopade (horse) – 1832: Doncaster Cup
- Galopade (horse sired by Royal Hampton) – 1907: Herzog von Ratibor-Rennen
Galopin
- Galopin – b. 1872
- Galopin (horse foaled c. 1924) – 1928: Prix Maurice de Gheest
Galoubet
- Galoubet (horse) – redirects to Galoubet A
- Galoubet (racehorse) – 1961: La Coupe
- Galoubet A – b. 1972 (show jumping)
Ganges
- Ganges (horse) – 1990–91: Critérium de Maisons-Laffitte, Prix Djebel
- Ganges (horse sired by Hannibal) – 1904: Preis des Winterfavoriten
Gangway
- Gangway (horse) – 1951: McLennan Handicap
- Gangway (horse sired by Saraband) – 1894: Stewards' Cup (Great Britain)
Garde a Vous
- Garde a Vous – 1988: Silberne Peitsche
- Garde a Vous (horse foaled c. 1940) – 1944: Prix du Pin
Garrick
- Garrick (horse) – 1950: Queen Anne Stakes
- Garrick (horse foaled in 1846) – 1848: Norfolk Stakes (Great Britain)
Gavarni
- Gavarni (horse) – 1877: Prix d'Ispahan
- Gavarni (horse sired by Macdonald II) – 1911: Prix Eugène Adam
Gazelle
- Gazelle (horse) – 1875: National Hunt Chase Challenge Cup
- Gazelle (horse sired by Sorcerer) – 1817: Newmarket Stakes
General
- General (Arabian horse) – 2009–10: Arabian World Cup
- General (horse) – 1870: Molecomb Stakes
- General (horse sired by Brigadier Gerard) – 1976: Prix Thomas Bryon
Gentilhomme
Getaway
- Getaway (horse) – 2006–10: Grand Prix de Deauville, Grosser Preis von Baden, Grosser Preis von Berlin, Jockey Club Stakes, Prix de Lutèce etc.
- Getaway (horse sired by Solonaway) – 1958: Phoenix Stakes
Ghuznee
- Ghuznee – 1841: Coronation Stakes, Epsom Oaks
- Ghuznee (horse sired by Palestro) – 1870: Goldene Peitsche
Giboulee
- Giboulee – 1976–78: Coronation Futurity Stakes, Dominion Day Stakes
- Giboulee (horse sired by Suzerain) – 1877: Grand Prix de Vichy-Auvergne, Prix Kergorlay
Gibraltar
- Gibraltar (horse) – 1919: Deutsches Derby
- Gibraltar (horse sired by Fitz James) – 1895: Prix Daniel Wildenstein
Gigolo
- Gigolo (horse) – (redirects to Gigolo FRH) – b. 1983 (dressage)
- Gigolo (horse foaled in 1905) – 1908: Prix Daru, Prix Juigné
- Gigolo (steeplechase horse) – 1955: List of Grand National first four placings
Gilded Vanity
- Gilded Vanity – 1981: Meld Stakes
- Gilded Vanity (horse sired by Orby) – 1918: Phoenix Stakes
Gilmore
- Gilmore (horse) – 1967: Toronto Cup Stakes
- Gilmore (horse sired by Kaiseradler) – 1983–84: Dr. Busch-Memorial, Grosser Preis der Wirtschaft
Gin
- Gin (horse) – 1857: July Stakes
- Gin (horse sired by Waldcanter) – 1969: Hessen-Pokal
Girolamo
- Girolamo (horse) – 2009–10: Jerome Stakes, Vosburgh Stakes, 2009 WTR, 2010 WTR
- Girolamo (horse sired by Dai Jin) – 2012: Preis von Europa
Gladstone
- Gladstone (horse) – 1963: Dr. Busch-Memorial, Union-Rennen
- Gladstone (horse foaled c. 1877) – 1881: November Handicap
- Gladstone (horse sired by Wild Dayrell) – 1863: St. James's Palace Stakes
Gladwin
- Gladwin (horse) – 1970: Hawthorne Gold Cup Handicap, Philip H. Iselin Stakes
- Gladwin (horse foaled c. 1898) – 1902: Portland Handicap
Glaneur
- Glaneur – 1869: Grand Prix de Paris
- Glaneur – 1932: see Pete Bostwick
Glencoe
- Glencoe I – b. 1831
- Glencoe II – b. 1864
Glengarry
- Glengarry (horse) – b. 1866, see Lieut. Gibson
- Glengarry (horse sired by Scottish Chief) – 1878: Prince of Wales's Stakes
Gloaming
- Gloaming (horse) – b. 1915
- Gloaming (horse foaled in 1937) – 1941: Lincoln Handicap
Go Between
- Go Between (horse) – 2006–08: Pacific Classic Stakes, Sunshine Millions Classic, Virginia Derby
- Go Between (horse sired by Highest Honor) – 1995–96: Prix de Condé, Prix Omnium II
- Go Between (horse sired by Meddler) – 1906: American Champion Older Male Horse
Golden Cloud
- Golden Cloud – b. 1932 (redirects to Trigger (horse))
- Golden Cloud (racehorse) – 1945: Nunthorpe Stakes
Golden Orb
Golden Sovereign
- Golden Sovereign – 1937–38: Gimcrack Stakes, Newmarket Stakes
- Golden Sovereign (horse sired by Whistler) – 1961: Curragh Stakes
Golden Sun
- Golden Sun (horse) – 1914–15: Challenge Stakes, July Cup, Stewards' Cup (Great Britain)
- Golden Sun (horse sired by Dr Fong) – 2003: Silver Tankard Stakes
Goldfinder
- Goldfinder (horse) – b. 1764
- Goldfinder (horse sired by Faugh-a-Ballagh) – 1853: Chester Cup
Goldoni
- Goldoni (horse) – 1896: Derby Italiano, St. Leger Italiano
- Goldoni (horse sired by Dylan Thomas) – 2012: Investec Derby Trial
Gondola
- Gondola (horse) – 1987: Deutsches St. Leger, Hamburger Stuten-Preis
- Gondola (horse sired by Weatherbit) – 1864: Yorkshire Oaks
Gondolier
- Gondolier (horse) – 1985: Durban July Handicap
- Gondolier (horse foaled c. 1827) – 1831: Ayr Gold Cup
Good Hope
- Good Hope (horse) – 1876: Union-Rennen
- Good Hope (horse sired by Cape Flyaway) – 1869: Ayr Gold Cup, Doncaster Cup
Good Luck
- Good Luck (horse) – 1949: Prix du Jockey Club
- Good Luck (horse sired by Royal Hampton) – 1899: Queen Anne Stakes
Good Morning
- Good Morning (horse) – 1942: Matron Stakes (United States)
- Good Morning (horse sired by Gallinule) – 1900: Coventry Stakes
- Good Morning (horse sired by Sir Cosmo) – 1944: Irish 2,000 Guineas
Goshawk
- Goshawk (horse) – 1922: Saratoga Special Stakes
- Goshawk (horse sired by Merlin) – 1826: Newmarket Stakes
Governor
- Governor (horse) – 1900: Poule d'Essai des Poulains, Prix de Guiche
- Governor (horse sired by Royal Oak) – 1843: Prix Daru
Gracchus
- Gracchus (horse) – 1934: Prix du Pin
- Gracchus (horse sired by Stani) – 1962: Preis des Winterfavoriten
Gracioso
- Gracioso (horse) – 1999: Prix Lupin
- Gracioso (horse sired by Poleax) – 1978: Oettingen-Rennen
Grafton
- Grafton (horse) – 1903–09: Leading sire in Australia
- Grafton (horse foaled in 1885) – 1888: Doncaster Cup
Grand Flaneur
- Grand Flaneur – b. 1877
- Grand Flaneur (horse foaled in 1870) – 1873–75: Portland Handicap
Grand Seigneur
- Grand Seigneur – 1999: Summit Juvenile Hurdle
- Grand Seigneur (horse sired by Vinicius) – 1910: Prix Saint-Roman
Grandmaster
- Grandmaster (horse) – 1883: Craven Stakes
- Grandmaster (horse sired by Grand Parade) – 1930: Wokingham Stakes
Grapeshot
- Grapeshot (horse) – 1996–97: Cocked Hat Stakes, Somerville Tattersall Stakes
- Grapeshot (horse sired by Alarm) – 1854: Northumberland Plate
Grasshopper
- Grasshopper (horse) – b. 1945 (eventing)
- Grasshopper (horse sired by Dixie Union) – 2007 WTRR, 2008 WTR
Gratitude
- Gratitude (horse) – 1955–57: Norfolk Stakes (Great Britain), Nunthorpe Stakes
- Gratitude (horse sired by Newminster) – 1865: Royal Hunt Cup
Greenback
- Greenback (horse) – 1995–96: Adonis Juvenile Novices' Hurdle, Wayward Lad Novices' Chase
- Greenback (horse sired by St Frusquin) – 1910: Prince of Wales's Stakes
Greta
- Greta (horse) – 1968: Del Mar Oaks
- Greta (horse foaled c. 1856) – 1860: Ayr Gold Cup
Greyhound
- Greyhound (horse) – b. 1932 (harness racing)
- Greyhound (horse sired by Mourne) – 1964: Prix Gladiateur
Guido Reni
- Guido Reni (horse) – 1911: Derby Italiano, Premio Parioli
- Guido Reni (horse sired by Blarney) – 1920: Prix de Barbeville
Guillotine
- Guillotine (horse) – 1949: Belmont Futurity Stakes
- Guillotine (horse sired by Montjeu) – 2008 World Thoroughbred Rankings
Gulliver
- Gulliver (horse) – 1888–89: Hardwicke Stakes, Richmond Stakes
- Gulliver II – 1912: Deutsches Derby, Hansa-Preis
Habibti
- Habibti – b. 1980
- Habibti (horse sired by Tabasco Cat) – 2001: Del Mar Debutante Stakes, Hollywood Starlet Stakes
Halcyon
Halston
- Halston (horse) – 1829: Chester Cup
- Halston (horse sired by Dark Legend) – 1931: Prix Fille de l'Air
Hambletonian
- Hambletonian (horse) – b. 1792
- Hambletonian 10 – b. 1849 (harness racing)
Hannibal
- Hannibal (horse) – b. 1801
- Hannibal (horse sired by Olambala) – 1918–19: Saratoga Special Stakes, Travers Stakes
- Hannibal (horse sired by Trachenberg) – 1894–1912: Deutsches St. Leger, Grosser Preis von Berlin, Hansa-Preis, Leading sire in Germany
Hapsburg
- Hapsburg (horse) – 1913–14: Champion Stakes, Eclipse Stakes, Norfolk Stakes (Great Britain)
- Hapsburg (horse sired by Anabaa) – 2008: Grand Prix de Vichy-Auvergne
Harbinger
- Harbinger (horse) – b. 2006
- Harbinger (horse sired by Galopin) – 1892–93: Craven Stakes, Molecomb Stakes, Sussex Stakes
Harmonious
- Harmonious (horse) – 1990 in sports (Hambletonian Stakes)
- Harmonious (horse) – 2010: American Oaks, Queen Elizabeth II Challenge Cup Stakes, 2010 WTR
Harris Tweed
- Harris Tweed (horse) – 2012: John Porter Stakes
- Harris Tweed (horse sired by Montjeu) – 2010: 2010 World Thoroughbred Rankings
Headache
- Headache (horse) – 2011: Hawthorne Gold Cup Handicap
- Headache (horse sired by Muhtathir) – 2005: Prix d'Arenberg
Hebridean
- Hebridean (horse) – 2008–09: Adonis Juvenile Novices' Hurdle, Gallinule Stakes
- Hebridean (horse sired by Norwick) – 1994: Long Distance Hurdle, Long Walk Hurdle
Hebron
- Hebron (horse) – 1902–04: Critérium de Maisons-Laffitte, Prix Perth, Prix du Pin
- Hebron (horse sired by Kilwarlin) – 1895: Wokingham Stakes
Helioscope
- Helioscope (horse) – 1954–55: Massachusetts Handicap, Philip H. Iselin Stakes, Pimlico Special
- Helioscope (horse sired by Hyperion) – 1949: Hardwicke Stakes
Helmet
- Helmet (horse) – 1908: Champagne Stakes (United States), Hopeful Stakes, Matron Stakes (United States)
- Helmet (horse sired by Trumpeter) – 1871: Norfolk Stakes (Great Britain)
Hennessy
- Hennessy (horse) – 1995: Hopeful Stakes, Sapling Stakes
- Hennessy (horse sired by Presenting) – 2009: Bet365 Gold Cup
Henry
- Henry (horse) – b. 1819, see Timoleon (horse)
- Henry (horse) – 1871–72: Ascot Gold Cup, King Edward VII Stakes
Hephestion
- Hephestion (horse) – b. 1807
- Hephestion (horse sired by Marske) – 1776: Craven Stakes
Her Highness
- Her Highness (horse) – 1890: Monmouth Breeders' Cup Oaks
- Her Highness (horse sired by Rex Magna) – 1987–88: Prix du Conseil de Paris, Prix de Royallieu
Herero
- Herero (horse) – 1962: Deutsches Derby, Mehl-Mülhens-Rennen
- Herero (horse sired by Elopement) – 1907: Bayerisches Zuchtrennen
Heresy
- Heresy (horse) – 1912: Queen's Plate
- Heresy (horse sired by Hermit) – 1890: Coronation Stakes
Hero
- Hero (horse) – 1895–96: Critérium International, Prix de Flore, Prix de la Forêt, Prix Jean-Luc Lagardère
- Hero (horse sired by Signal Light) – 1951: Prix Fille de l'Air
Herold
- Herold (horse) – 1920–33: Deutsches Derby, Deutsches St. Leger, Grosser Preis von Berlin, Leading sire in Germany
- Herold (horse sired by Fulmen) – 1894: Mehl-Mülhens-Rennen
Hervine
- Hervine – 1851–52: Prix du Cadran, Prix de Diane, Prix Gladiateur
- Hervine (horse foaled in 1884) – 1887: Prix Vanteaux
Hibernia
- Hibernia (horse) – 1963: Irish Oaks, Pretty Polly Stakes (Ireland)
- Hibernia (horse sired by Faugh-a-Ballagh) – 1859: Royal Whip Stakes
Hidalgo
- Hidalgo (horse) – 1886: Philip H. Iselin Stakes
- Hidalgo (horse foaled in 1951) – 1954: Gallinule Stakes, Royal Whip Stakes
- Hidalgo (horse sired by Macherio) – 1955: Gran Criterium
High Game
- High Game (horse) – 1970–71: La Coupe, Prix du Lys
- High Game (horse sired by Le Solaret) – 2000: Mildmay Novices' Chase
High Roller
- High Roller (horse) – 1977: Cup and Saucer Stakes, Display Stakes
- High Roller (horse sired by Generous) – 1996: Autumn Stakes (Great Britain)
High Stakes
- High Stakes (horse) – 1999: Prestbury Juvenile Novices' Hurdle
- High Stakes (horse sired by Hyperion) – 1946: Ormonde Stakes
Highlander
- Highlander (horse) – 1933: Dee Stakes
- Highlander (horse sired by Norseman) – 1949: Prix Juigné
Hippolytus
- Hippolytus (horse) – 2011: June 2011 in sports
- Hippolytus (horse sired by Emilius) – 1851: Dee Stakes
His Eminence
- His Eminence (horse) – b. 1898
- His Eminence (horse sired by Fastnet) – 1945: Prix Noailles
- His Eminence (horse sired by Royal Hampton) – 1906: Craven Stakes
His Reverence
- His Reverence – 1896: St. James's Palace Stakes
- His Reverence (horse sired by Duncan Gray) – 1933: Phoenix Stakes
Hoche
- Hoche (horse) – 1972: Premio Presidente della Repubblica, see Celtic Ash
- Hoche (horse sired by Robert the Devil) – 1893–94: Prix Exbury, Prix du Gros Chêne, Prix de Meautry
Honeysuckle
- Honeysuckle (horse) – 1921–22: Prix de Malleret, Prix du Petit Couvert, Prix de Pomone, Prix Vanteaux
- Honeysuckle (horse sired by Touchstone) – 1854: Park Hill Stakes
Horatius
- Horatius (horse) – 1980: Red Bank Stakes
- Horatius (horse sired by Asterus) – 1941: Prix du Conseil de Paris
Hortensia
- Hortensia (horse) – 1980: Prix Cléopâtre, Prix de l'Opéra
- Hortensia (horse foaled in 1947) – 1950: Prix de Royaumont
Horus
- Horus (horse) – 2006: Greatwood Gold Cup
- Horus (horse foaled in 1908) – 1910: Prix des Réservoirs
- Horus (horse sired by Papyrus) – 1929: King Edward VII Stakes, Sagaro Stakes
Hunter's Moon
- Hunter's Moon (horse) – 1939–40: Cesarewitch Handicap, Prix Juigné, White Rose Stakes
- Hunter's Moon (horse sired by Hurry On) – 1929: Newmarket Stakes
Hymettus
Ibrahim
- Ibrahim (horse) – b. 1952 (show jumping sire)
- Ibrahim (racehorse) – 1835: 2,000 Guineas Stakes
Icelandic
- Icelandic (horse) – 1977–79: Beresford Stakes, Chester Vase, Gladness Stakes, John Porter Stakes
- Icelandic (horse sired by Selkirk) – 2006–07: Premio Chiusura, Premio del Piazzale
Idas
- Idas (horse) – 1845: 2,000 Guineas Stakes, Newmarket Stakes, St. James's Palace Stakes
- Idas (horse foaled in 1948) – 1950: Prix du Bois
If
Ilex
- Ilex (horse) – 1890–92: List of Grand National winners, List of Grand National first four placings
- Ilex (horse foaled in 1928) – 1931: Prix Eugène Adam
Illinois
- Illinois (horse) – 1901: Critérium de Saint-Cloud
- Illinois (horse sired by Tenerani) – 1958: Duke of York Handicap
Illo
- Illo – 2010–11: Grand Prix-Aufgalopp, Grosser Preis der Wirtschaft (disq.)
- Illo (horse sired by Florizel II) – 1909: Bayerisches Zuchtrennen
Imperatrice
- Imperatrice – b. 1938
- Imperatrice (horse sired by Orlando) – 1862: Park Hill Stakes
Imperial
- Imperial (horse) – 1912: Prix Noailles
- Imperial (horse sired by Imi) – 1964: Hansa-Preis
Imperioso
- Imperioso – 2004: Olympics – Individual dressage, Olympics – Team dressage
- Imperioso (racehorse) – 1999–2000: Frühjahrs Dreijährigen-Preis, Hessen-Pokal
Impressionist
- Impressionist (horse) – 1997: Futurity Stakes (Ireland)
- Impressionist (horse sired by Prunus) – 1928: Hansa-Preis
Incitatus
- Incitatus (horse) – 1997–2000: Barbados Gold Cup, Connaught Cup Stakes, King Edward Stakes
- Incitatus (horse sired by Energy) – 1891: Prix des Chênes, Prix de la Salamandre
- Incitatus (horse sired by Sicambre) – 1956: Prix Jean Prat
Independence
- Independence (horse) – 2001: Matron Stakes (Ireland), Sun Chariot Stakes
- Independence (horse sired by Filho da Puta) – 1831: Chester Cup
Indian Queen
- Indian Queen – b. 1985
- Indian Queen (horse sired by Melton) – 1894: Cambridgeshire Handicap
Indra
Indus
- Indus (horse) – 1930–31: Critérium de Maisons-Laffitte, Poule d'Essai des Poulains, Prix Jean-Luc Lagardère
- Indus (horse foaled in 1893) – 1896: Prix Juigné
Inkerman
- Inkerman (horse) – 1923–24: Chester Vase, Jockey Club Stakes
- Inkerman (horse sired by Vaguely Noble) – 1978: Gallinule Stakes, Irish Champion Stakes
Inlander
- Inlander (horse) – 1933: Travers Stakes
- Inlander (horse sired by Ile de Bourbon) – 1987: Imperial Cup, Swinton Handicap Hurdle
Innishowen
- Innishowen – 1993: Stardom Stakes
- Innishowen (horse sired by Uncas) – 1875: Irish Derby
Insight
- Insight (horse) – 1998: Prix de l'Opéra
- Insight (horse sired by Oversight) – 1926: Cambridgeshire Handicap
Insulaire
- Insulaire – 1878–79: King Edward VII Stakes, Prix du Jockey Club, Queen Alexandra Stakes
- Insulaire (horse sired by Aureole) – 1969: Prix Minerve
Iona
Irian
- Irian (horse) – 1979–81: Maghull Novices' Chase, MCR Hurdle
- Irian (racehorse) – b. 2006
Iron Mask
- Iron Mask (horse) – 2000: Prix d'Arenberg
- Iron Mask (horse sired by Disguise) – 1911: Challenge Stakes
- Iron Mask (horse sired by Juggernaut) – 1924: Seaton Delaval Stakes
Iroquois
- Iroquois (horse) – b. 1878
- Iroquois (horse sired by Arco) – 1952: Gran Premio d'Italia, Premio Presidente della Repubblica
Isabella
- Isabella (horse) – 1860–61: Poule d'Essai des Poulains, Prix Jean-Luc Lagardère
- Isabella (horse sired by Springy Jack) – 1859: Preis der Diana
Isoline
- Isoline (horse) – 1863: Goodwood Cup
- Isoline (horse sired by Klairon) – 1965: Prix de Pomone
Ivanhoe
- Ivanhoe (horse) – 1919: Cesarewitch Handicap
- Ivanhoe (horse sired by Phantom) – 1820: Newmarket Stakes
Ivoire
- Ivoire – 1900–01: Prix du Cadran, Prix du Pin, Prix Royal-Oak
- Ivoire (horse foaled in 1904) – 1906: Prix des Réservoirs
Ixia
- Ixia (horse) – 1907: Prix de Barbeville
- Ixia (horse sired by Rossendale) – 1925: Irish Oaks
Jack High
- Jack High – 1928: Hopeful Stakes
- Jack High – 2005–07: Bet365 Gold Cup, 2006 Grand National, 2007 Grand National
Jacobus
- Jacobus (horse) – 1883: Preakness Stakes
- Jacobus (steeplechase horse) – 1915–16: List of Grand National first four placings
Jaguar Mail
- Jaguar Mail – 2008: Equestrian at the 2008 Summer Olympics – Individual jumping
- Jaguar Mail – 2008–10: 2008 WTR, 2009 WTR, 2010 WTR
Janitor
- Janitor (horse) – 1866: Jersey Stakes
- Janitor (horse sired by Fervor) – 1932–35: Goldene Peitsche, Herzog von Ratibor-Rennen, Preis des Winterfavoriten
Jannette
- Jannette – b. 1875
- Jannette (horse sired by King Bladud) – 1811: Ascot Gold Cup
Janus
- Janus (horse) – 1949–50: Prix Jean Prat, Prix La Rochette
- Janus (horse sired by Buchan) – 1933: Hansa-Preis
- Janus (horse sired by King Tom) – 1861: King Edward VII Stakes
- Janus (horse sired by Ragstone) – 1984: Lanzarote Hurdle
- Janus (steeplechase horse) – 1855: List of Grand National first four placings
Javelot
- Javelot – 1959–61: Eclipse Stakes, Prix Dollar, Prix de Fontainebleau, Prix Ganay, Prix d'Ispahan
- Javelot (horse sired by Fitz Herbert) – 1926–28: Grand Prix de Vichy-Auvergne, La Coupe de Maisons-Laffitte, Prix La Force
Jazz Band
- Jazz Band (horse) – 1979: Prix Isonomy
- Jazz Band (horse sired by Polyphonic) – 1924: Northumberland Plate
Jenny
- Jenny (horse) – 1868: Prix de Diane
- Jenny (horse sired by Royal Oak) – 1843: Prix Gladiateur
Jenny Lind
- Jenny Lind (horse) – 1955: Lancashire Oaks
- Jenny Lind (horse sired by Fulmen) – 1897: Goldene Peitsche
Jerry
- Jerry (horse) – b. 1821
- Jerry (racehorse) – b. 1830s
Jester
- Jester (horse) – 1982–83: Duke of York Stakes, Phoenix Sprint Stakes
- Jester (horse sired by Merrymaker) – 1876–78: Cesarewitch Handicap, Queen Anne Stakes
Joe Miller
- Joe Miller (horse) – 1894: Queen's Plate
- Joe Miller (horse sired by Venison) – 1852: Ascot Gold Cup, Chester Cup
Johannesburg
- Johannesburg (horse) – b. 1999
- Johannesburg (horse sired by Romulus) – 1974: Prix du Pin
John Bull
- John Bull (horse) – b. 1789
- John Bull (horse sired by Actaeon) – 1844: Union-Rennen
John o' Gaunt
- John o' Gaunt (horse) – b. 1901, see Assault (horse)
- John o' Gaunt (horse sired by Taurus) – 1841: Newmarket Stakes
Jongleur
- Jongleur (horse) – 1876–78: Cambridgeshire Handicap, Prix d'Ispahan, Prix Jean-Luc Lagardère, Prix du Jockey Club, Prix Royal-Oak etc.
- Jongleur (horse sired by Sayajirao) – 1956: Blandford Stakes, Desmond Stakes, Royal Whip Stakes
Joshua
- Joshua (horse) – 1971: Challenge Stakes, Prix du Chemin de Fer du Nord, Prix Messidor
- Joshua (horse sired by Childwick) – 1902: Hardwicke Stakes
- Joshua (horse sired by Marsyas) – 1953: Prix du Gros Chêne
Julius Caesar
- Julius Caesar (horse) – 1980: Prix Noailles
- Julius Caesar (horse sired by St Albans) – 1878: Royal Hunt Cup
Junior
- Junior (horse) – 2008: Winter Novices' Hurdle
- Junior (horse sired by Symington) – 1913: Ebor Handicap
Jupiter Pluvius
- Jupiter Pluvius (horse) – 2007: Killavullan Stakes
- Jupiter Pluvius (horse sired by Aureole) – 1974: Chester Vase
Justus
- Justus (horse) – 1946: Åby Stora Pris
- Justus (horse sired by Luciano) – 1978: Bayerisches Zuchtrennen
Juveigneur
- Juveigneur (horse) – 1919–20: Prix Berteux, Prix Kergorlay, Prix Vicomtesse Vigier
- Juveigneur (horse sired by Funny Baby) – 2005: Fulke Walwyn Kim Muir Challenge Cup
Kaiser
- Kaiser (horse) – b. 1975
- Kaiser (horse sired by Skirmisher) – 1872–73: Champagne Stakes (Great Britain), Prince of Wales's Stakes
Kate Kearney
- Kate Kearney – 1834: July Stakes
- Kate Kearney (horse foaled c. 1812) – 1816: Ayr Gold Cup
Keystone
- Keystone (horse) – 1940: Cheveley Park Stakes
- Keystone II – 1906: Coronation Stakes, Epsom Oaks
Kildare
- Kildare (horse) – 1886: Anglesey Stakes, Railway Stakes (Ireland)
- Kildare (horse foaled in 1829) – 1831: Anglesey Stakes
Kilkenny
- Kilkenny (horse) – b. 1957 (eventing horse)
- Kilkenny (racehorse) – 1865: Portland Handicap
Kindergarten
- Kindergarten (horse) – b. 1937
- Kindergarten (horse sired by Trempolino) – 1992: Prix d'Aumale
King Cole
- King Cole (horse) – 1870: King Edward VII Stakes, St. James's Palace Stakes
- King Cole (horse sired by Memnon) – 1838: Chester Cup
King James
- King James (horse) – b. 1905
- King James (horse sired by English Prince) – 1982: Prix Quincey
- King James (horse sired by Perth) – 1907: Prix d'Hédouville
King of Clubs
- King of Clubs (horse) – 1984–85: Earl of Sefton Stakes, Premio Carlo Vittadini, Premio Federico Tesio, Premio Ribot, Premio Vittorio di Capua
- King of Clubs (horse foaled in 1920) – 1926: Lincoln Handicap
King of Diamonds
- King of Diamonds (horse) – Successful ISH Showjumpers
- King of Diamonds (racehorse) – 1859–70: Champagne Stakes (Great Britain), Leading sire in Germany
King of Rome
- King of Rome (horse) – 2008: Meld Stakes, Royal Whip Stakes, 12th 2008 Epsom Derby
- King of Rome (horse sired by King of the Tudors) – 1974: Lane's End Stakes
King William
- King William (horse) – 1992: Badminton Horse Trials
- King William (horse sired by Orest) – 1871: Newmarket Stakes
- King William (horse sired by William the Third) – 1910–11: Dewhurst Stakes, King Edward VII Stakes
Kingcraft
- Kingcraft – b. 1867
- Kingcraft (horse sired by Samaritain) – 1960: Grand Steeple-Chase de Paris
Kingfisher
- Kingfisher (horse) – b. 1867
- Kingfisher (horse sired by Alcide) – 1967: Irish 2,000 Guineas (disq.)
Kingston
- Kingston (horse) – b. 1884
- Kingston (horse sired by Venison) – 1852–53: Goodwood Cup, Northumberland Plate
Knight Errant
- Knight Errant (horse) – 1958: Galway Hurdle
- Knight Errant (horse sired by Knight of the Garter) – 1883: Seaton Delaval Stakes
Knight of the Garter
- Knight of the Garter (horse) – 1923: Coventry Stakes
- Knight of the Garter (horse sired by The Prime Minister) – 1869: Chester Cup
Koh-i-Noor
- Koh-i-Noor (horse) – 1916: American Champion Two-Year-Old Filly
- Koh-i-Noor (horse sired by The Provost) – 1854: Union-Rennen
Kong
- Kong (horse) – 2005: Lingfield Derby Trial, 13th 2005 Epsom Derby
- Kong (horse sired by Baytown) – 1937: Wokingham Stakes
Ksar
- Ksar (horse) – b. 1918
- Ksar (horse sired by Kalydon) – 1973–74: Brigadier Gerard Stakes, Lingfield Derby Trial, Prix Gontaut-Biron, Sandown Classic Trial
La Belle
- La Belle (horse) – 1962: Diadem Stakes
- La Belle (horse sired by Fourire) – 1906: Critérium de Saint-Cloud
Labrador
- Labrador (horse) – 1895–96: Champion Stakes, Jersey Stakes, July Stakes
- Labrador (horse sired by Biribi) – 1940: Prix Chaudenay
Ladislas
- Ladislas (horse) – 1882–83: Dewhurst Stakes, Jockey Club Cup, King Edward VII Stakes
- Ladislas (horse foaled in 1902) – 1904: Prix de la Salamandre
Lady Rebecca
- Lady Rebecca – 1999–2001: Cleeve Hurdle
- Lady Rebecca (horse sired by Sir Ivor) – 1974: Prix Vanteaux
Lady's View
- Lady's View (horse) – 1968: Seaton Delaval Stakes
- Lady's View (horse sired by Panorama) – 1944: Phoenix Stakes
Ladylove
- Ladylove – 1875: Jersey Stakes
- Ladylove (horse sired by Fels) – 1916: Goldene Peitsche
Lahib
- Lahib – 1992: Queen Anne Stakes, Queen Elizabeth II Stakes
- Lahib (Arabian horse) – 2008: Arabian World Cup
Lahire
- Lahire (horse) – 1910–12: Prix de Lutèce, Prix Perth, Prix Saint-Roman
- Lahire (horse sired by Xaintrailles) – 1894: Prix de Guiche
Lamplighter
- Lamplighter (horse) – 1892–93: American Champion Older Male Horse, Champion Stakes (United States)
- Lamplighter (horse sired by Merlin) – 1828: Craven Stakes
Lara
- Lara (horse) – 2006: Ind. freestyle dressage at Equestrian Games, Ind. special dressage at Equestrian Games
- Lara (racehorse) – 1996: Premio Sergio Cumani
Las Vegas
- Las Vegas (horse) – 1984: Deutsches St. Leger, Preis der Diana, Rheinland-Pokal
- Las Vegas (horse foaled c. 1942) – 1946: November Handicap
Laser Light
Launay
- Launay (horse) – 1894–97: Poule d'Essai des Poulains, Prix Jean Prat, Prix du Prince d'Orange, Prix de la Salamandre
- Launay (horse sired by Caldarium) – 1958: Prix Jean Prat
Laureate
- Laureate (horse) – 1968: Dee Stakes, Lingfield Derby Trial
- Laureate (horse sired by Petrarch) – 1889–91: Cambridgeshire Handicap, Royal Hunt Cup
- Laureate (horse sired by Rosicrucian) – 1882: Craven Stakes
Le Duc
- Le Duc – 2003: Anniversary 4-Y-O Novices' Hurdle
- Le Duc (horse sired by Flamingo) – 1937: Prix d'Harcourt
Le Glorieux
- Le Glorieux – b. 1984
- Le Glorieux (horse sired by Frontin) – 1891: Prix du Pin
Le Marmot
- Le Marmot – 1978–80: Prix Foy, Prix Ganay, Prix Greffulhe, Prix Hocquart, Prix La Rochette, Prix Niel
- Le Marmot (horse sired by Le Gosse) – 1940: Prix de Condé, Prix Saint-Roman
Leeds
- Leeds (horse) – 1996: 8th 1996 Prix de l'Arc de Triomphe
- Leeds (horse foaled c. 1880) – 1884: Portland Handicap
Leichtsinn
- Leichtsinn – 1957: Preis des Winterfavoriten
- Leichtsinn (horse sired by Ard Patrick) – 1923: Grosser Preis der Landeshauptstadt Düsseldorf
Lena
- Lena (horse) – 1913: Goldene Peitsche
- Lena II – 1901: Prix de Flore
Leo
- Leo (horse) – b. 1940 (Quarter Horse)
- Leo (horse sired by Pivotal) – 2005: Royal Lodge Stakes
Leonard
- Leonard (horse) – 1946: List of Cox Plate winners
- Leonard (horse sired by Golden Myth) – 1933: Northumberland Plate
Leonidas
- Leonidas (horse) – 1930: Lincoln Handicap
- Leonidas (horse sired by Kronzeuge) – 1973: Grosse Europa-Meile
Les Arcs
- Les Arcs (horse) – 2006: Diamond Jubilee Stakes, July Cup, 2006 WTRR
- Les Arcs (horse sired by Top Ville) – 1985: Feilden Stakes
Levanter
- Levanter (horse) – 1901: List of Grand National first four placings
- Levanter (horse sired by Le Levanstell) – 1971: Cocked Hat Stakes, Craven Stakes
Leviathan
- Leviathan (horse) – 1826–48: Dee Stakes, Leading sire in North America
- Leviathan (horse sired by Luciano) – 1977: Frühjahrs Dreijährigen-Preis
Lexicon
- Lexicon (horse) – 1999: Ancient Title Stakes
- Lexicon (horse sired by Theologian) – 1900: November Handicap
Libertine
- Libertine (horse) – 1950–51: Breeders' Stakes, Cup and Saucer Stakes
- Libertine (horse sired by Hello Gorgeous) – 1987: Premio Federico Tesio
Licata
- Licata (horse) – 1972: Prix Cléopâtre, Prix de Malleret
- Licata (horse sired by Dschingis Khan) – 1975–76: German 1,000 Guineas, Herzog von Ratibor-Rennen
Light Cavalry
- Light Cavalry (horse) – 1980–81: King Edward VII Stakes, Princess of Wales's Stakes, St. Leger Stakes
- Light Cavalry (horse foaled c. 1946) – 1950: Northumberland Plate
Lilium
- Lilium (horse) – 2000: Oh So Sharp Stakes
- Lilium (horse foaled c. 1930) – 1934: Prix Jean de Chaudenay
Limbo
- Limbo (dressage horse) – 2004: Equestrian at the 2004 Summer Olympics – Individual dressage
- Limbo (horse) – 1977–78: Mehl-Mülhens-Rennen, Union-Rennen, Zukunfts-Rennen
Limelight
- Limelight (horse) – 1932–33: Duke of York Handicap, Hardwicke Stakes, Jersey Stakes
- Limelight (horse) – 1954: Belmont Stakes Top three finishers
Linacre
- Linacre (horse) – 1916–18: Leading sire in Australia
- Linacre (horse sired by Rockefella) – 1963–64: International Stakes (Ireland), Irish 2,000 Guineas, Prix de la Porte Maillot, Queen Elizabeth II Stakes
Linden Tree
- Linden Tree (horse) – 1877: see Clay Trotting Horses
- Linden Tree (racehorse) – 1970–71: Chester Vase, Racing Post Trophy
Link Boy
- Link Boy – 1931: Greenham Stakes
- Link Boy (horse sired by Aladdin) – 1827: Goodwood Cup
Lion
Lion Hearted
- Lion Hearted – 1929: Prince of Wales Stakes
- Lion Hearted (horse sired by Sir Gallahad) – 1929: Prix Quincey
Lion Tamer
- Lion Tamer (horse) – 2003–04: Cigar Mile Handicap, Hutcheson Stakes top three finishers and starters
- Lion Tamer (horse sired by Storming Home) – 2010: 2010 World Thoroughbred Rankings
Lionel
- Lionel (horse) – 1966–67: Grand Prix de Deauville
- Lionel (horse sired by St Nicholas) – 1851: Union-Rennen
Loadstone
- Loadstone (horse) – 1851: Stewards' Cup (Great Britain)
- Loadstone (horse foaled in 1841) – 1843: Anglesey Stakes
Lochiel
- Lochiel (horse) – 1897–1906: Leading sire in Australia
- Lochiel (horse sired by Coronach) – 1933: Craven Stakes
Loiterer
- Loiterer – 1877: Belmont Stakes Top three finishers
- Loiterer (horse sired by Sorcerer) – 1810: Ascot Gold Cup
Lomond
- Lomond (horse) – b. 1980
- Lomond (horse sired by Desmond) – 1911–13: Gimcrack Stakes, Norfolk Stakes (Great Britain), Queen Anne Stakes
- Lomond (horse sired by Preciptic) – 1965–66: Ebor Handicap, Princess of Wales's Stakes
Longbow
- Longbow (horse) – 1853: Stewards' Cup (Great Britain)
- Longbow (horse sired by The Bard) – 1899: Prix de Barbeville
Longchamps
- Longchamps (horse) – 2000: Equestrian at the 2000 Summer Olympics – Eventing Individual
- Longchamps (racehorse) – 1868: Prix du Cadran
Lord Derby
- Lord Derby (horse) – 1972: San Luis Obispo Handicap
- Lord Derby (horse foaled c. 1869) – 1873: Ayr Gold Cup
Lord Jim
- Lord Jim (horse) – 1971: William Hill Trophy
- Lord Jim (horse sired by Kahyasi) – 1997: Bristol Novices' Hurdle
Lorimer
- Lorimer (horse) – 1979: Preis der Sparkassen-Finanzgruppe
- Lorimer (horse sired by Within-the-Law) – 1947: Royal Whip Stakes
Lottery
- Lottery (horse) – b. 1830
- Lottery (horse sired by Tramp) – 1825: Doncaster Cup
Lovelace
- Lovelace (horse) – 1931–32: Prix de la Forêt, Prix du Gros Chêne, Prix d'Ispahan, Prix du Prince d'Orange
- Lovelace (horse sired by Royal Applause) – 2007–08: Oettingen-Rennen, Supreme Stakes
Lucetta
Lucius
- Lucius (horse) – 1978: List of Grand National winners, List of Grand National first four placings
- Lucius (horse sired by Antonio Canale) – 1964: Grosse Europa-Meile
Lucknow
Lui
- Lui (horse) – 2006: Individual jumping at World Equestrian Games, Malaysia at World Equestrian Games
- Lui (racehorse) – 1925–26: Derby Italiano, Gran Premio d'Italia, Premio Roma
Lupus
- Lupus (horse) – 1861: Jersey Stakes
- Lupus (horse sired by Herold) – 1928: Deutsches Derby, Deutsches St. Leger, Union-Rennen
Lydia