| Jagoda | | yah-GAW-dah (Polish) | Croatian, Serbian, Macedonian, Polish | |
| Jagusia | | yah-GUW-shah | Polish | |
| Jakub | | YAH-kuwp (Polish) | Polish, Czech, Slovak | |
| Jan (1) | | YAHN (Dutch, Swedish, Norwegian, Polish, German) | Dutch, Swedish, Norwegian, Danish, Czech, Polish, Slovene, German, Catalan | |
| Janek | | YAH-nek (Polish) | Polish, Czech | |
| Janina | | yah-NEE-nah (Polish, German), YAH-nee-nah (Finnish) | Polish, Finnish, German, Swedish, Lithuanian | |
| Janusz | | YAH-nuwsh | Polish | |
| Jarek | | YAH-rek (Polish) | Polish, Czech | |
| Jarogniew | | yah-RAWG-nyef | Polish (Rare) | |
| Jaromir | | yah-RAW-meer | Polish | |
| JaropeŁK | | yah-RAW-pewk | Polish | |
| JarosŁAw | | yah-RAW-swahf | Polish | |
| JarosŁAwa | | yah-raw-SWAH-vah | Polish | |
| Jerzy | | YE-zhi | Polish | |
| Joachim | | zho-a-KEEM (French), YO-ah-khim (German), yo-AH-khim (German), yaw-AH-kheem (Polish), JO-ə-kim (English) | French, German, Polish, Judeo-Christian Legend | |