| Challenger II | |
|---|---|
| Sire | Swynford |
| Grandsire | John O'Gaunt |
| Dam | Sword Play |
| Damsire | Great Sport |
| Sex | Stallion |
| Foaled | 1927 |
| Country | Ireland |
| Colour | Bay |
| Breeder | The National Stud |
| Owner | 1) Lord Dewar 2) William L. Brann & Robert S. Castle |
| Trainer | Fred Darling |
| Record | 12: 2-0-1 |
| Earnings | US$ |
| Major wins | |
| Clearwell Stakes (1929) Richmond Stakes (1929) | |
| Awards | |
| Leading sire in North America (1939) | |
Challenger (1927–1948) was an Irish Thoroughbred racehorse who became a Leading sire in North America.