| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| Iacomus | - | Late Roman | ||
| Iacopo | - | Italian | ||
| Iael | - | Biblical Greek | ||
| Iafeth | - | Biblical Latin | ||
| Iago | ee-A-gaw (Welsh, Galician), ee-AH-go (English) | Welsh, Galician, Portuguese | ||
| Iah | - | Egyptian Mythology | ||
| Iahel | - | Biblical Latin | ||
| Iahmesu | - | Ancient Egyptian | ||
| Iair | - | Biblical Latin, Biblical Greek | ||
| Iairos | - | Biblical Greek | ||
| Iairus | - | Biblical Latin | ||
| Iakob | - | Georgian | ||
| Iakobos | - | Biblical Greek | ||
| Iakopa | - | Hawaiian | ||
| Iakovu | - | Old Church Slavic |