| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| JÁChym | - | Czech | ||
| JÉRÉMie | - | French | ||
| JÉRÔMe | zhe-ROM | French | ||
| JÓHann | - | Icelandic | ||
| JÓHanna | - | Icelandic | ||
| JÓHannes | - | Icelandic, Faroese | ||
| JÓN | - | Icelandic, Faroese | ||
| JÓNa | - | Icelandic | ||
| JÓNas | - | Icelandic | ||
| JÓNatan | - | Icelandic | ||
| JÓRunnr | - | Ancient Scandinavian | ||
| JÚLia | ZHOO-lyə (Portuguese), YOO-lee-aw (Hungarian) | Portuguese, Catalan, Hungarian, Slovak | ||
| Jaala | - | Biblical | ||
| Jaap | YAH:P | Dutch | ||
| Jaasau | - | Biblical |