| Name | Color | Sex | Year of birth | Microchip | Sire | Dam | Breed | Breeder |
|---|---|---|---|---|---|---|---|---|
| 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 | |
| Willnt | bay | f | 1978 | Nostrum | Chateaurullah | Thoroughbred | USA | |
| Willonyx | br. | c | 1907 | William The Third | Tribonyx | Thoroughbred | Great Britain | |
| Willow Ann | chestnut | f | 1942 | Solario | Court of Appeal | Thoroughbred | Great Britain | |
| Willow Dale | bay | f | 1993 | Danehill | Miss Willow Bend | Thoroughbred | Ireland | |
| Willow Dare | bay | f | 1957 | Thoroughbred | USA | |||
| Willow Hour | bay | c | 1978 | Bold Hour | Cherry Willow | Thoroughbred | USA | |
| Willow Lake | br. | f | 1955 | Windfields | Thoroughbred | Canada |