| Jingyi | | - | Chinese | |
| Jiro | | jee-ṙo: | Japanese | |
| Jirou | | jee-ṙo: | Japanese | |
| JoĈJo | | YO-chyo | Esperanto | |
| JoÃO | | ZHWOWN, zhoo-OWN | Portuguese | |
| JoÃOzinho | | - | Portuguese | |
| Joana | | - | Portuguese, Catalan | |
| Joaninha | | - | Portuguese | |
| Joaquim | | - | Portuguese, Catalan | |
| Joel | | JOL (English), JO-əl (English), ho-EL (Spanish), zhoo-EL (Portuguese), YO-el (Swedish, Finnish) | English, Spanish, Portuguese, Swedish, Finnish, Biblical | |
| Johanna | | yo-HAH-nah (German), yo-HAHN-nah (Danish, Dutch), YO-hahn-nah (Finnish) | German, Swedish, Norwegian, Danish, Dutch, Hungarian, Finnish, Estonian, English, Late Roman | |
| Johannes | | yo-HAH-nes (German), yo-HAHN-nəs (Dutch, Danish), YO-hahn-nes (Finnish) | German, Dutch, Swedish, Norwegian, Danish, Finnish, Estonian, Late Roman | |
| Johano | | yo-HAH-no | Esperanto | |
| Joosep | | - | Estonian | |
| JordÃO | | - | Portuguese | |