| Nikica | | - | Croatian, Serbian | |
| Nikifor | | - | Russian, Bulgarian, Macedonian | |
| Nikita (1) | | nee-KEE-tah (Russian) | Russian, Ukrainian, Belarusian | |
| Nikki | | NIK-ee | English | |
| Nikkole | | ni-KOL | English (Rare) | |
| 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 | |
| Nikodim | | - | Russian, Macedonian | |
| Nikola (1) | | - | Serbian, Croatian, Slovene, Bulgarian, Macedonian, Hungarian, Czech, Basque, Medieval Slavic | |
| Nikola (2) | | NEE-ko-lah (German) | German, Polish, Czech, Slovak | |
| Nikolai | | nee-kah-LIE (Russian) | Russian, Bulgarian | |
| Nikolaj | | - | Danish, Slovene | |
| Nikolao | | nee-ko-LAH-o | Esperanto | |