| Name | Country | Region | Address |
|---|---|---|---|
| Willy Lockhart, Lockhart Quintana Hermanos | Uruguay | ||
| Wilma Mooij-Jan der Wal | Netherlands | ||
| Wilmsdorf | Germany | ||
| Wilnjusskij, ks | Lithuania | ||
| Wimberley Bloodstock, LLC | USA | ||
| Winchell Thoroughbreds, LLC | USA | ||
| Winchester Place Thoroughbreds, LLC & Matt Jackson | USA | ||
| Wind Hill Farm | USA | ||
| Windylea Farm-New York, LLC | USA | ||
| Winner's Farm | USA |