| Name | Color | Sex | Year of birth | Microchip | Sire | Dam | Breed | Breeder |
|---|---|---|---|---|---|---|---|---|
| 3951-6 Youwontseeme | chestnut | f | 2009 | Pulpit | Three of a Kind | Thoroughbred | USA | |
| Ypres | black | f | 1957 | Yildiz | My Rose | Thoroughbred | USA | |
| Yron Marschal | c | Thoroughbred | ||||||
| Yrrah Jr | bay | c | 1964 | Ribot | Ola | Thoroughbred | USA | |
| Ys | bay | f | 1951 | Vatellor | Thoroughbred | France | ||
| Yser | chestnut | f | 1922 | Pommern | Thoroughbred | Great Britain | ||
| Yu Like Mi | bay | f | 2023 | 900217000169114 | 1673-7 Mister Laki | 5700-7 Yunona | Thoroughbred | Donskoi Stud |
| Yu-uil-si | bay | f | 1886 | Le-Panisel | Miss Alis | Thoroughbred | ||
| Yubilej | bay | c | 1995 | 3759-1 Lunn's Particular | 5957 Mimoza | Thoroughbred | Derkul Stud | |
| 940 Yubilej | bay | c | 1931 | 25 Bransi | 350 Yungfrau | Thoroughbred | Voskhod Stud |