| Name | Color | Sex | Year of birth | Microchip | Sire | Dam | Breed | Breeder |
|---|---|---|---|---|---|---|---|---|
| Thessalie | chestnut | f | 1897 | Thoroughbred | France | |||
| Theta | f | 1962 | Round Table | Delta | Thoroughbred | |||
| Thetis II | chestnut | f | 1957 | Thoroughbred | Great Britain | |||
| Thewayyouare | bay | c | 2005 | Kingmambo | Maryinsky | Thoroughbred | USA | |
| They Call Me Red | chestnut | c | 2010 | 643094100137212 | Spring At Last | Paris Wild Cat | Thoroughbred | USA |
| Thianges | grey | f | 1906 | Gardefeu | Madame de Maintenon | Thoroughbred | France | |
| Thicket | bay | f | 1947 | Nasrullah | Thorn Wood | Thoroughbred | Great Britain | |
| Thidiot | chestnut | f | 1941 | Invermark | Fairy Ring | Thoroughbred | USA | |
| Thiella | bay | f | 1976 | Busted | Seaswan | Thoroughbred | Great Britain | |
| Thill | d.-bay | f | 1974 | Iron Ruler | Ta Wee | Thoroughbred | USA |