瓦西里（俄语：Васи́лий）起源于希腊语的斯拉夫语族男性人名。

这个名字的来源是古希腊语中的单词“王”（Βασιλεύς，有时音译为巴塞鲁斯）。需要注意的是，古希腊的“巴塞鲁斯”的地位与职能与古代中国和欧洲的“国王”不完全相同。

The name Basil (/ˈbæzəl/; royal, kingly) comes from the male Greek name Vassilios (Greek:Βασίλειος, female version Bασιλική), which first appeared during the Hellenistic period. It is derived from "basileus" (Greek:βασιλεύς), a Greek word of pre-Hellenic origin meaning "king", from which words such as basilica and basilisk (via Latin) as well as the eponymous herb (via Old French) derive, and the name of the Italian region Basilicata, which had been long under the rule of the Byzantine Emperor (also called basileus).