Cognomen Василиос (Vasileios 
, Vasilios , Vassilios , along with others...) , in all the world, is a widespread family name. The family name Василиос is characteristic of Greece, where it is a prevalent surname, North Macedonia, where it is quite a rare surname, and Cyprus. Measured by absolute frequency, it most frequently occurs in Greece, Bulgaria, and North Macedonia. Also, Василиос is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Vasileios, Vassilios, Vasilios | Greece, Australia, Germany, United States, United Kingdom |
| Βασίλειος | Greece |
| Wasilios | Germany, Brazil, Poland, United States, Switzerland |
| Василиос | Russia, Bulgaria |
Basil, Basile, Basileios, Basili, Basilide, Basilio, Basilius, Basos, Basílio, Bazil, Bazilij, Bazilo, Bazyli, Lakis, Pasi, Vasil, Vasil', Vasile, Vasili, Vasilii, Vasilij, Vasilije, Vasilis, Vasiliy, Vasily, Vasos, Vassil, Vassileios, Vassili, Vassilis, Vassyl, Vasyl, Vaszil, Vaszilij, Vazul, Wasil, Wasilij, Wasos, Wassil, Wassili, Wassily, Wassyl, Wasyl, Βάσος, Βασίλης, Λάκης, Базил, Базиле, Базили, Базилий, Базилио, Базило, Базилій, Басиль, Безіл, Бэзил, Вазул, Васил, Василе, Василевс, Василие, Василий, Василис, Василије, Василь, Василій, Вассил, Вассили, Вассілі, Васыль, Васька, Вася, Васіль, Васілій, Паси, Վասիլի, וסילי, باسيل, فاسيل, فاسيلي, واصل, ვასილ, ვასილი, バジル, and 瓦西里
Зиакас, Матфеопуло, and Ангелопулос