The olive, botanical name Olea europaea, meaning 'European olive' in Latin, is a species of small tree or shrub in the family Oleaceae, found traditionally in the Mediterranean Basin. When in shrub form, it is known as Olea europaea 'Montra', dwarf olive, or little olive. The species is cultivated in all the countries of the Mediterranean, as well as in Australia, New Zealand, North and South America and South Africa. It is the type species for its genus, Olea. The tree and its fruit give their name to the Oleaceae plant family, which also includes species such as lilac, jasmine, forsythia, and the true ash tree.

The olive's fruit, also called an "olive", is of major agricultural importance in the Mediterranean region as the source of olive oil; it is one of the core ingredients in Mediterranean cuisine. Thousands of cultivars of the olive tree are known. Olive cultivars may be used primarily for oil, eating, or both. Olives cultivated for consumption are generally referred to as "table olives". About 80% of all harvested olives are turned into oil, while about 20% are used as table olives.