| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| Iairus | - | Biblical Latin | ||
| Iakob | - | Georgian | ||
| Iakobos | - | Biblical Greek | ||
| Iakopa | - | Hawaiian | ||
| Iakovu | - | Old Church Slavic | ||
| Iancu | - | Romanian | ||
| Iantha | - | Various | ||
| Ianuarius | - | Ancient Roman | ||
| Ianus | - | Roman Mythology | ||
| Iapetus | - | Greek Mythology (Latinized) | ||
| Iapheth | - | Biblical Greek | ||
| Iared | - | Biblical Latin, Biblical Greek | ||
| Iason | - | Greek Mythology, Ancient Greek, Greek, Biblical Greek, Biblical Latin | ||
| Ib | - | Danish | ||
| Ibai | - | Basque |