| 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 | |
| Joanna | | jo-AN-ə (English), yaw-AHN-nah (Polish) | English, Polish, Biblical | |
| Joasia | | yaw-AH-shah | Polish | |
| Jola | | - | Polish | |
| Jolanta | | yaw-LAHN-tah (Polish) | Polish, Lithuanian | |
| Jowita | | yaw-VEE-tah | Polish | |