| Greggory | One who is alert and watchful. |
| Gregoire | A person who is very vigilant. |
| Gregoly | A variant meaning watchful guardian. |
| Gregoriana | One who is alert and observant. |
| Gregorie | A classic name meaning vigilant. |
| Gregorior | A rare name meaning the vigilant. |
| Gretal | A name meaning a small pearl. |
| Grete | A name meaning a tiny pearl. |
| Griffin | Fierce; Having a hooked nose; Mythological Beast; Strong in faith.; Surname. |
| Grigorov | Son of the watchful guardian. |
| Gruev | A Bulgarian name meaning a fierce one. |
| Gryphon | Mythological beast |
| Gryta | A name meaning a cooking vessel. |
| GUILIO | An Italian name meaning youthful. |
| GYES | myth name (a Titan) |
| Gyoergy | A Hungarian form of George. |
| Gyorgy | A Hungarian name meaning farmer. |
| Gyuri | A Hungarian form of George. |
| Hades | king of the dead |
| HAEMON | myth name (son of Creon) |
| HAIDEE | A name meaning modest or shy. |
| Halcyon | Calm. Derived from the name of a Greek mythological sea bird. Commonly used in the expression 'halcyon days.'. |
| HALCYONE | myth name (daughter of Aeolus) |
| Haldis | A stone spirit or protector. |
| HALI | Derived from the Greek for sea. |
| HALIMEDA | thinking of the sea |
| HALIRRHOTHIUS | myth name (son of Poseidon) |
| Halithersis | Seer who warns Penelope's suitors. |
| HARALAMBOS | meaning unknown |
| HARMONIA | myth name (daughter of Ares) |
| HASIONE | A name of Greek mythological origin. |
| Haydee | Modest and wellbehaved. |
| HEBE | myth name (goddess of youthful beauty) |
| Hecate | Greek goddess of fertility who later became associated with Persephone as goddess of the underworld and protector of witches |
| HECUBA | myth name (mother of Paris and Hector) |
| Hedea | A pleasant and sweet personality. |
| HEDIA | One who is pleasant and charming. |
| Hedyla | A name meaning sweet or pleasant one. |
| Hehe | Goddess of youthful beauty. |
| Hekuba | Mother of Paris and Hector. |