Olivia is conventionally translated as "olive tree," from the Latin oliva. But scholars at our reference suggest the truth is more interesting. Olivia is most likely a feminine form of Oliver, which traces not to the olive but to the Old Germanic name Alfher, composed of alf (elf) and hari (army, warrior). The "olive" reading is folk etymology — a beautiful misreading propagated for centuries.
Whatever its true origin, Olivia was popularised by William Shakespeare, who used it in 1601 as the name of a much-courted aristocrat in Twelfth Night. By 2019 it had displaced Emma to become the most popular girl name in the United States, where it has remained for five years running.
Its appeal is the easy sound, the soft Liv nickname, and a meaning that almost everyone is happy to believe.
In Pythagorean numerology the letters of Olivia reduce to 5, The Seeker. This is a traditional interpretive system, not a factual claim about the name.