| Name | Color | Sex | Year of birth | Microchip | Sire | Dam | Breed | Breeder |
|---|---|---|---|---|---|---|---|---|
| Union Rags | bay | c | 2009 | Dixie Union | Tempo | Thoroughbred | USA | |
| Unite | f | Kris | Thoroughbred | |||||
| United Holme | bay | c | 1974 | Noholme II | Smoke Veil | Thoroughbred | USA | |
| Unity | bay | f | 1962 | Tudor Melody | Real Tesoro | Thoroughbred | Great Britain | |
| Unity Hall | f | 1968 | Cyane | Rum Bottle Bay | Thoroughbred | USA | ||
| Univer | bay | c | 2024 | 643090000705215 | 1084-5 Russian Favourite | 4848-6 Unikalnaya | Thoroughbred | Mr Bolokov R.A. |
| Universal Star | bay | f | 1998 | Unfuwain | Shirley Superstar | Thoroughbred | Great Britain | |
| Universalnaya | bay | f | 1995 | 3261-1 Staur | 8011 Bella | Thoroughbred | Derkul Stud | |
| Universiada | chestnut | f | 2011 | 985101045169028 | Papal Bull | Jordecca | Thoroughbred | Ireland |
| Universitet | chestnut | c | 2006 | 643098100103855 | 0378-3 Terrestrial | 1124-3 Ufa | Thoroughbred | "Nalchikskii" halvichnyi zavod |