Which sea lies between mainland Greece and Turkey?

The sea between mainland Greece and Turkey is the Aegean Sea.

The Aegean is a northeastern arm or embayment of the Mediterranean Sea, lying between Greece’s Balkan mainland and Turkey’s Anatolian peninsula. It stretches northward toward the Dardanelles, which lead through the Sea of Marmara and Bosporus to the Black Sea. Its island-filled waters form one of the most recognizable maritime landscapes in Europe.

More than 150 islands and islets are associated with the Aegean, including Crete, Euboea, Rhodes, Lesbos, and the Cyclades. Most of the main islands belong to Greece, while Turkey administers Bozcaada and Gökçeada. The region’s volcanic history is visible at islands such as Santorini and Milos, where past eruptions shaped coastlines and soils.

The Aegean also has major historical importance. Ancient Greek trade, colonization, warfare, and mythology developed around its harbors and islands. It is sometimes confused with the Ionian Sea, which lies west of mainland Greece, or the Tyrrhenian Sea, west of Italy. Modern Greece–Turkey disputes include maritime boundaries, airspace, and rights over surrounding waters.