Across the world, Nikolai, Nikolaj (Nikolai, Nikolaj 
) is a very rare male given name. The first name Nikolai, Nikolaj is characteristic of Western Europe, particularly Germany, where it is a very rare male name.
| VARIANT | COUNTRY |
|---|---|
| Nikolai, Nikolaj | Germany |
Mikalai, Mikalaj, Mikalay, Mikałaj, Miklavž, Miklos, Miklós, Mikola, Mikołaj, Mikuláš, Mikławš, Mykola, Mykoła, Niccolò, Nicholas, Nickel, Nicolaas, Nicolae, Nicolaes, Nicolas, Nicolau, Nicolay, Nicolino, Nicolo, Nicolás, Nicolò, Nicos, Nicu, Niels, Nikolai, Nikolaj, Nikolajs, Nikolajus, Nikolao, Nikolaos, Nikolas, Nikolass, Nikolaus, Nikolay, Nikolaz, Nikolaï, Nikolos, Nikoloz, Nikos, Nikołaj, Nikulás, Nils, Nyikolaj, Νίκολας, Νίκος,