| Thecla | | - | Dutch (Rare), Late Greek (Latinized) | |
| Theia | | - | Greek Mythology | |
| Thekla | | - | German (Rare), Greek (Rare), Late Greek | |
| Themis | | - | Greek Mythology | |
| Themistocles | | - | Ancient Greek (Latinized) | |
| Themistokles | | - | Ancient Greek | |
| Themistoklis | | - | Greek | |
| Theocritus | | - | Ancient Greek (Latinized) | |
| Theodora | | thee-ə-DAWR-ə (English) | English, Greek, Ancient Greek | |
| Theodoros | | - | Greek, Ancient Greek | |
| Theodorus | | - | Ancient Greek (Latinized), Dutch | |
| Theodosia | | - | Ancient Greek, Greek | |
| Theodosios | | - | Ancient Greek | |
| Theodosius | | - | Ancient Greek (Latinized) | |
| Theodotos | | - | Ancient Greek | |