| Name | Color | Sex | Year of birth | Microchip | Sire | Dam | Breed | Breeder |
|---|---|---|---|---|---|---|---|---|
| William of Valence | br. | c | 1932 | Vatout | Thoroughbred | France | ||
| William Rufus | chestnut | c | 1900 | Melton | Thoroughbred | Great Britain | ||
| William The Thir | chestnut | c | 1815 | Thoroughbred | Great Britain | |||
| William The Third | bay | c | 1898 | St. Simon | Gravity | Thoroughbred | Great Britain | |
| William's Pride | bay | f | 1911 | William The Third | Stop Her | Thoroughbred | Great Britain | |
| Williams Forester | chestnut | c | 1750 | Crofts Forester | Looby Mare | Thoroughbred | Great Britain | |
| Williams High | grey | c | 2015 | 643093300024832 | 0827-5 Highest Lover | 4561-6 Woody Land | Thoroughbred | Mr Botashev D.Kh. |
| Williams Woodstock Arabian | grey | c | Thoroughbred | |||||
| Williamstone | d.-bay | c | 1990 | Seattle Slew | Winter Sparkle | Thoroughbred | USA | |
| Willing Maid | chestnut | f | 1972 | Olden Times | Lady o'War | Thoroughbred | USA |