| Name | Color | Sex | Year of birth | Microchip | Sire | Dam | Breed | Breeder |
|---|---|---|---|---|---|---|---|---|
| X.L. | bay | f | 1862 | Polish | Judy Go | Thoroughbred | Ireland | |
| Xaar | bay | c | 1995 | Zafonic | Monroe | Thoroughbred | Great Britain | |
| Xaintrailles | c | 1882 | Thoroughbred | |||||
| 3477-5 Xanadu Beach | chestnut | f | 2006 | Western Borders | Five Stars | Thoroughbred | USA | |
| Xandover | grey | c | 1927 | Condover | Xanthina | Thoroughbred | France | |
| Xanthina | f | Thoroughbred | ||||||
| Xanthina | d.-bay | f | 1930 | My Play | Killimick | Thoroughbred | USA | |
| Xaymaca | bay | f | 1970 | Jamaico | Eatonia | Thoroughbred | SAF | |
| Xerantheme | bay | f | 1886 | Thoroughbred | France | |||
| Ximeno | c | 1944 | Full Sail | Thoroughbred | Argentina |