| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| Jan (1) | YAHN (Dutch, Swedish, Norwegian, Polish, German) | Dutch, Swedish, Norwegian, Danish, Czech, Polish, Slovene, German, Catalan | ||
| Jana (1) | YAH-nah (Dutch, German) | Czech, Slovak, Dutch, German, Slovene, Catalan | ||
| Janek | YAH-nek (Polish) | Polish, Czech | ||
| JaniČKa | - | Czech | ||
| Jarek | YAH-rek (Polish) | Polish, Czech | ||
| Jarka | - | Czech | ||
| Jarmil | - | Czech | ||
| Jarmila | - | Czech, Slovak | ||
| JaromÍR | - | Czech | ||
| Jaroslav | - | Czech, Slovak | ||
| Jaroslava | - | Czech, Slovak | ||
| JiŘÍ | - | Czech | ||
| JiŘIna | - | Czech | ||
| JindŘIch | - | Czech | ||
| Jitka | - | Czech |