The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Europe and Anatolia, on the south by North Africa, and on the east by the Levant. The sea is sometimes considered a part of the Atlantic Ocean, although it is often identified as a completely separate body of water.

The name Mediterranean is derived from the Latin mediterraneus, meaning "inland" or "in the middle of the land" (from medius, "middle" and terra, "land"). It covers an approximate area of 2.5 million km² (965,000 sq mi), but its connection to the Atlantic (the Strait of Gibraltar) is only 14 km (8.7 mi) wide. In oceanography, it is sometimes called the Eurafrican Mediterranean Sea or the European Mediterranean Sea to distinguish it from mediterranean seas elsewhere.

The Mediterranean Sea has an average depth of 1,500 m (4,900 ft) and the deepest recorded point is 5,267 m (17,280 ft) in the Calypso Deep in the Ionian Sea.

It was an important route for merchants and travelers of ancient times that allowed for trade and cultural exchange between emergent peoples of the region — the Mesopotamian, Persian, Egyptian, Phoenician, Carthaginian, Iberian, Greek and Byzantine, Roman and Italian, Illyrian, Thracian, Levantine, Gallic, Arabic, Berber, Jewish, Aragonese, Nubian, Slavic and Turkish cultures. The history of the Mediterranean region is crucial to understanding the origins and development of many modern societies. "For the three quarters of the globe, the Mediterranean Sea is similarly the uniting element and the centre of World History."