Its source is Olivier, a French name meaning "Olive tree."
This boy's name is used in Italian.
The prototype of this name was one of Charlemagne's knights, celebrated in the 12th-century poem Chanson de Roland.
The French source suggests the name ultimately evolved from the Latin term olivarius. However, the companions-in-arms of the original French knight in the Chanson all sported names of clearly Germanic derivation. Keeping that in mind, other possible sources include the Old German name Alfihar (host of elves) and the Old Norse name Olafr (ancestor).