Hymettus, also Hymettos (Gr. Hymêttó or Hymittôs, old spelling Imittós) is a mountain range in Athens Area, East Central Greece. It was known as Trelovouno until the beginning of the 20th century. The height is 1,026 m and the length is 16 km (10 mi) between Athens and the Saronic Gulf and 6 to 7 km from east to west. It ws noted for honey. Marble has been quarried since its antiquity. The neighboring communities that surround the mountain are Athens, Zografou, Kaisariani, Vyron, Ilissium, Helioupoli, Elliniko, Glyfada, Voula and Vouliagmeni in the west, Varkiza, Vári, Markopoulo and Paeania to its east, and Papagou, Aghia Paraskevi, Gerakas and Glyka Nera. Most of the forest is in the north, and much of the mountain is rocky, deforested, grassy and made out of limestone.

Today has a university near its mountain range. A landfill for Athens area is there, a forest park on the western portion of the mountain, Attiki Odos freeway (began in 2000 and opened in 2003) and the houses is surrounding the northern half of the mountain, Vouliagmeni, Vári, and Várkiza is to its south, Ellinikon International Airport and Athens is to its west. Houses from the southern suburbs are built on the southern and western half of the mountain range. A transmitter tower that carries television and radio signals to the southwestern half of Attica or Athens is mounted with about 8 of them next to the mountain top. Urban housing almost surrounds the entire mountain range

Almost all of Athens, eastern suburbs, and the new airport can be seen from the mountaintop along with a few mountains of Parnitha, Penteli, and Aegaleo.

See also: List of mountains in Greece