| Name | Color | Sex | Year of birth | Microchip | Sire | Dam | Breed | Breeder |
|---|---|---|---|---|---|---|---|---|
| Yesterday Morn | d.-bay | f | 1971 | Amber Morn | Pin Lass | Thoroughbred | USA | |
| Yesteryear | bay | f | 2002 | Green Desert | Western Appeal | Thoroughbred | Great Britain | |
| Yetive | f | Thoroughbred | ||||||
| Yetta | f | 1970 | Ragusa | Tyronera | Thoroughbred | Great Britain | ||
| Yettajet | bay | f | 1981 | Tri Jet | Three Up | Thoroughbred | USA | |
| Yeuse | bay | f | 1963 | Tosco | Fleur du Lude | Thoroughbred | Great Britain | |
| Yevros | bay | c | 2011 | 953000010008789 | 0553-4 Almakhtub | 2141-4 Evridika | Thoroughbred | "Rassvet" |
| Yildiz | chestnut | c | 1948 | Mahmoud | Ace Card | Thoroughbred | USA | |
| Yippingale | bay | f | 1909 | William The Third | Chelandry | Thoroughbred | Great Britain | |
| Yo Ali | d.-bay | f | 2002 | Quiet American | Tackalac | Thoroughbred | USA |