| Iohannes | | - | Biblical Latin | |
| Iohel | | - | Biblical Latin | |
| Iona (2) | | - | Russian, Georgian, Biblical Latin | |
| Ionas | | - | Biblical Greek, Biblical Latin | |
| Ionathan | | - | Biblical Greek, Biblical Latin | |
| Ioram | | - | Biblical Latin, Biblical Greek | |
| Iosaphat | | - | Biblical Latin, Biblical Greek | |
| Ioseph | | - | Biblical Greek, Biblical Latin | |
| Iosias | | - | Biblical Latin, Biblical Greek | |
| Iosue | | - | Biblical Latin | |
| Isaac | | IE-zək (English) | English, Jewish, Biblical, Biblical Latin | |
| Ismahel | | - | Biblical Latin | |
| Israhel | | - | Biblical Latin | |
| Ithamar | | - | Biblical, Biblical Latin, Biblical Greek | |
| Iudas | | - | Biblical Latin | |