The Hellenic Trench (HT) is an oceanic trough located in the forearc of the Hellenic arc, an arcuate archipelago on the southern margin of the Aegean Sea plate, or Aegean Plate, also called Aegea, the basement of the Aegean Sea. The HT begins in the Ionian Sea near the mouth of the Gulf of Corinth and curves to the south, following the margin of the Aegean Sea. It passes close to the south shore of Crete and ends near the island of Rhodes just offshore Anatolia.
In the classical theory of its origin the HT is an oceanic trench containing the Hellenic subduction zone, directly related to the subduction of the African plate under the Eurasian plate. Alternate views developed later on additional data question the classical view postulating that the HT may be the result wholly or partially of back-arc extension and slab rollback. The "partial" view hypothesizes that the western leg of the HT, Ionian Sea east to eastern Crete, exhibits the line of subduction and therefore is an oceanic trench. The "not at all" view, relying on the theory that the subduction line is under or south of the Mediterranean Ridge, questions whether any of the HT is currently subductional. If not, it is merely a legacy, a remnant of a previous subduction zone that has gone elsewhere.