The olive tree, Olea europaea, is an evergreen tree or shrub native to the Mediterranean Asia and Africa. It is short and squat, and rarely exceeds 8–15 m (26–49 ft) in height. The Pisciottana, a unique variety comprising 40,000 trees found only in the area around Pisciotta in the Campania region of southern Italy often exceeds this, with correspondingly large trunk diameters. The silvery green leaves are oblong, measuring 4–10 cm (1.6–3.9 in) long and 1–3 cm (0.39–1.18 in) wide. The trunk is typically gnarled and twisted.

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It seems certain that the olive tree as we know it today had its origin approximately 6,000 to 7,000 years ago in the region corresponding to ancient Persia and Mesopotamia.[15] The olive plant later spread from these countries to nearby territories corresponding to present-day Syria, Lebanon, Israel and the Palestinian territories.

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The edible olive seems to have coexisted with humans for about 5,000 to 6,000 years, going back to the early Bronze Age (3150 to 1200 BC). Its origin can be traced to areas along the eastern Mediterranean coast in what are now southern Turkey, Syria, Lebanon, Palestine, and Israel based on written tablets, olive pits, and wood fragments found in ancient tombs.[17] At least one cookbook writer has posited that the most ancient evidence of olive cultivation is found in Syria, Israel, and Crete.

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The immediate ancestry of the cultivated olive is unknown. It is assumed[by whom?] that Olea europaea may have arisen from O. chrysophylla in northern tropical Africa and that it was introduced into the countries of the Mediterranean Basin via Egypt and then Crete or the Levant, Syria, Tunisia and Asia Minor.[citation needed] Fossil Olea pollen has been found in Macedonia, Greece, and other places around the Mediterranean, indicating that this genus is an original element of the Mediterranean flora. Fossilized leaves of Olea were found in the palaeosols of the volcanic Greek island of Santorini (Thera) and were dated about 37,000 BP. Imprints of larvae of olive whitefly Aleurolobus (Aleurodes) olivinus were found on the leaves. The same insect is commonly found today on olive leaves, showing that the plant-animal co-evolutionary relations have not changed since that time. Other leaves found on the same island are dated back to 60,000 BP, making them the oldest known olives from the Mediterranean.

As far back as 3000 BC, olives were grown commercially in Crete; they may have been the source of the wealth of the Minoan civilization.