| NIKLAS | | NIK-lahs (Swedish), NEEK-lahs (Finnish) | Swedish, Finnish, Danish, Norwegian, German | |
| NIKLAUS | | - | German (Swiss) | |
| NIKO | | NEE-ko (Finnish) | Finnish, Croatian, Slovene | |
| NIKODEM | | nee-KAW-dem | Polish | |
| NIKODEMOS | | - | Ancient Greek, Biblical Greek | |
| NIKODIM | | - | Russian, Macedonian | |
| NIKOL | | - | Czech, Bulgarian | |
| NIKOLA (1) | | - | Serbian, Croatian, Slovene, Bulgarian, Macedonian, Hungarian, Czech, Basque, Medieval Slavic | |
| NIKOLA (2) | | NEE-ko-lah (German) | German, Polish, Czech, Slovak | |
| NIKOLAAS | | - | Dutch | |
| NIKOLAI | | nee-kah-LIE (Russian) | Russian, Bulgarian | |
| NIKOLAJ | | - | Danish, Slovene | |
| NIKOLAJS | | - | Latvian | |
| NIKOLAO | | nee-ko-LAH-o | Esperanto | |
| NIKOLAOS | | - | Ancient Greek, Greek | |