| Jeblar | 1982 | Alydar系 |
| Jack Atkin | 1904 | St. Simon系 |
| Jackdaw | 1908 | Bend Or系 |
| Jack High | 1926 | Pot 8 o's系 |
| Jean Valjean | 1926 | The Tetrarch系 |
| Jet Action | 1951 | Blenheim系 |
| Jet Pilot | 1944 | Blenheim系 |
| Jigg | 1705 | Herod系 |
| Jock | 1936 | Teddy系 |
| Joe Andrews | 1778 | Eclipse系 |
| John o'Gaunt | 1901 | Pot 8 o's系 |
| John P. Grier | 1917 | Pot 8 o's系 |
| Jolly Jet | 1963 | Blenheim系 |
| Jukebox | 1966 | Owen Tudor系 |
| Junior | 1909 | Hampton系 |
| (アラ) Jussuf | 1869 | Arab父系 |