The older an olive tree is, the broader and more gnarled its trunk appears. Many olive trees in the groves around the Mediterranean are said to be several centuries old, and in some cases this has been verified scientifically.

An olive tree in Algarve, Portugal, is 2000 years old, according to radiocarbon dating. Pliny the Elder told of a sacred Greek olive tree that was 1,600 years old. Several trees in the Garden of Gethsemane (from the Hebrew words "gat shemanim" or olive press) in Jerusalem are claimed to date back to the time of Jesus. Some Italian olive trees are believed to date back to Roman times, although identifying progenitor trees in ancient sources is difficult. One olive tree in Bar, Montenegro, is claimed to be over 2,000 years old. Also, the age of an olive tree in Crete, claimed to be over 2,000 years old, has been determined on the basis of tree ring analysis. Another well-known olive tree on the island of Brijuni (Brioni), Istria in Croatia, has been calculated to be about 1,600 years old. It still gives fruit (about 30 kg. per year), which is made into top quality olive oil.

An olive tree in west Athens, named "Plato's Olive Tree", was rumoured to be a remnant of the grove within which Plato's Academy was situated, which would date it to approximately 2,400 years ago. The tree was a cavernous trunk from which a few branches were still sprouting in 1975, when a traffic accident caused a bus to fall on and uproot it. Since then the trunk is preserved and displayed in the nearby Agricultural University of Athens. A supposedly even older tree, called the "Peisistratos Tree", is located by the banks of the Cephisus River, in the municipality of Agioi Anargyroi, and is said to be a remnant of an olive grove planted by Athenian tyrant Peisistratos in the 6th century BC.

According to a recent scientific survey, there are dozens of ancient olive trees throughout Israel and Biblical Palestine, 1,600-2,000 years old, from even before the rise of Islam. Specifically, two giant olive trees in the Arab town of Arraba and five trees in Deir Hanna, both in the Galilee region, have been determined to be over 3,000 years old. All seven trees continue to produce olives.

The information above, regarding the age of olive trees in Israel must be considered carefully, as there is no credible scientific attribution to the survey or the estimate of 3000 years for the Arraba or Deir Hanna trees. A tree located in Santu Baltolu di Carana (municipality of Luras) in Sardinia, Italy, named with respect as the Ozzastru by the inhabitants of the region, is claimed to be 3,000 to 4,000 years old according to different studies. In the same natural garden, a few other millenary trees can be admired.

The olive is one of the plants most often cited in literature. In Homer's Odyssey, Odysseus crawls beneath two shoots of olive that grow from a single stock, and in the Iliad, is a metaphoric description of a lone olive tree in the mountains, by a spring; the Greeks observed that the olive rarely thrives at a distance from the sea, which in Greece invariably means up mountain slopes. Greek myth attributed to the primordial culture-hero Aristaeus the understanding of olive husbandry, along with cheese-making and bee-keeping. Olive was one of the woods used to fashion the most primitive Greek cult figures, called xoana, referring to their wooden material; they were reverently preserved for centuries. It was purely a matter of local pride that the Athenians claimed that the olive grew first in Athens.

In an archaic Athenian foundation myth, Athena won the patronship of Attica from Poseidon with the gift of the olive. Though, according to the 4th-century BC father of botany, Theophrastus, olive trees ordinarily attained an age of about 200 years, he mentions that the very olive tree of Athena still grew on the Acropolis; it was still to be seen there in the 2nd century AD; and when Pausanias was shown it, ca 170 AD, he reported "Legend also says that when the Persians fired Athens the olive was burnt down, but on the very day it was burnt it grew again to the height of two cubits." Indeed, olive suckers sprout readily from the stump, and the great age of some existing olive trees shows that it was perfectly possible that the olive tree of the Acropolis dated to the Bronze Age.

The olive was sacred to Athena and appeared on the Athenian coinage. The Roman poet Horace mentions it in reference to his own diet, which he describes as very simple:

"As for me, olives, endives, and smooth mallows provide sustenance." Lord Monboddo comments on the olive in 1779 as one of the foods preferred by the ancients and as one of the most perfect foods.