The name Flavius is a Roman family name meaning "golden" or "yellow-haired" (it is derived from the Latin word "flavus" meaning "yellow, golden").
Famous bearers
This was the family name of the Roman emperors Vespasian, Titus and Domitian, who ruled from 69 to 96.
Another bearer is Flavius Josephus (or just Josephus), a famous historian of the 1st century who took his Roman name from his patron Vespasian.