| Name | Color | Sex | Year of birth | Microchip | Sire | Dam | Breed | Breeder |
|---|---|---|---|---|---|---|---|---|
| Syncronise | bay | f | 1970 | Thoroughbred | Great Britain | |||
| Syndaar | bay | f | 1978 | Lyphard | Sweet And Lovely | Thoroughbred | France | |
| Synergistic | d.-bay | f | 1999 | Kris S | J. E.'s Connection | Thoroughbred | USA | |
| Synformer | bay | f | 1987 | Sovereign Dancer | Anjelicco | Thoroughbred | USA | |
| Synok | d.-bay | c | 2022 | 643090000485369 | 1071-5 Sweet Ducky | 3451-5 Victorious Athena | Thoroughbred | Mr Yukhigov N.S. |
| Syntactic | bay | f | 1974 | Forward Pass | War Tide | Thoroughbred | USA | |
| Syonora | bay | f | 1907 | Santoi | Feu Follet | Thoroughbred | Great Britain | |
| Syphon | chestnut | c | 1750 | Squirt | Thoroughbred | Great Britain | ||
| Syracuse | bay | f | 1985 | Sharp-Eyed Quillo | Segesta | Thoroughbred | USA | |
| 3398-5 Syrdarya | chestnut | f | 2008 | 0458-4 Akbash | 0990-3 Strofa | Thoroughbred | Voskhod Stud |