| Karsten | | KAHR-sten (Low German) | Low German, Danish, Norwegian | |
| Kasper | | KAHS-per (Polish, Swedish), KAHS-pər (Dutch) | Polish, Dutch, Swedish, Norwegian, Danish | |
| Katarina | | kah-tah-REE-nah (German, Swedish) | German, Swedish, Norwegian, Danish, Hungarian, Croatian, Serbian, Slovene | |
| Katharina | | kah-tah-REE-nah (German, Swedish) | German, Swedish, Norwegian, Danish | |
| Kathrine | | - | Danish, Norwegian | |
| Katja | | KAHT-yah (German, Dutch) | German, Swedish, Norwegian, Danish, Dutch, Slovene | |
| Katrine | | kaht-REE-ne (Danish) | Danish, Norwegian | |
| Kay (3) | | KIE (Swedish) | Frisian, German, Swedish, Norwegian, Danish | |
| Kennet | | - | Swedish, Norwegian, Danish | |
| Kenneth | | KEN-ith (Scottish, English) | Scottish, English, Swedish, Norwegian, Danish | |
| Ketil | | - | Norwegian | |
| Kevin | | KEV-in (English) | English, Irish, French, German, Dutch, Swedish, Norwegian, Danish | |
| Kim (2) | | KEEM (Finnish) | Danish, Swedish, Norwegian, Finnish | |
| Kine | | - | Norwegian | |
| Kirsten | | KEER-sten (Danish, Norwegian), KUR-stən (English) | Danish, Norwegian, English | |