| Iole | | - | Greek Mythology | |
| Ion (2) | | - | Greek Mythology | |
| Ionas | | - | Biblical Greek, Biblical Latin | |
| Ionathan | | - | Biblical Greek, Biblical Latin | |
| Ione | | ie-O-nee (English), IE-o-nee (English), ie-ON (English) | Greek Mythology, English | |
| Ioram | | - | Biblical Latin, Biblical Greek | |
| Iosaphat | | - | Biblical Latin, Biblical Greek | |
| Ioseph | | - | Biblical Greek, Biblical Latin | |
| Ioses | | - | Biblical Greek | |
| Iosias | | - | Biblical Latin, Biblical Greek | |
| Iosif | | ee-O-seef (Russian), YO-seef (Romanian) | Russian, Romanian, Greek | |
| Iou | | - | Biblical Greek | |
| Ioubal | | - | Biblical Greek | |
| Ioudas | | - | Biblical Greek | |
| Ioudith | | - | Biblical Greek | |