| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| Izabel | - | Portuguese (Brazilian) | ||
| Izumi | ee-zoo-mee | Japanese | ||
| JÁKup | - | Faroese | ||
| JÓAnnes | - | Faroese | ||
| JÓHannes | - | Icelandic, Faroese | ||
| JÓN | - | Icelandic, Faroese | ||
| JÔNatas | - | Portuguese | ||
| JÚLia | ZHOO-lyə (Portuguese), YOO-lee-aw (Hungarian) | Portuguese, Catalan, Hungarian, Slovak | ||
| Jaagup | - | Estonian | ||
| Jaak | - | Estonian, Flemish | ||
| Jaakob | - | Finnish (Rare), Estonian (Rare) | ||
| Jaan | - | Estonian | ||
| JacÓ | - | Portuguese | ||
| Jacinta | hah-THEEN-tah (Spanish), hah-SEEN-tah (Latin American Spanish) | Spanish, Portuguese | ||
| Jacinto | hah-THEEN-to (Spanish), hah-SEEN-to (Latin American Spanish) | Spanish, Portuguese |