| Name | Color | Sex | Year of birth | Microchip | Sire | Dam | Breed | Breeder |
|---|---|---|---|---|---|---|---|---|
| Therapia | bay | f | 1944 | Panorama | Thoroughbred | Great Britain | ||
| Thereby | f | Thoroughbred | ||||||
| Theresa | f | Zeddaan | Tamina | Thoroughbred | Germany | |||
| Theresina | chestnut | f | 1927 | Diophon | Teresina | Thoroughbred | Great Britain | |
| These Eyes | chestnut | f | 1999 | Belong to Me | Sally's Ride | Thoroughbred | USA | |
| Thesky'sthelimit | d.-bay | f | 1993 | Northern Prospect | Portio | Thoroughbred | USA | |
| Thessa | chestnut | f | 1895 | Thoroughbred | Austria | |||
| Thessalie | chestnut | f | 1897 | Thoroughbred | France | |||
| Theta | f | 1962 | Round Table | Delta | Thoroughbred | |||
| Thetis II | chestnut | f | 1957 | Thoroughbred | Great Britain |