Pelion or Pelium (Greek: Πήλιο Pilio, Ancient/Katharevousa: Πήλιον) is a mountain at the southeastern part of Thessaly in central Greece, forming a hook-like peninsula between the Pagasetic Gulf and the Aegean Sea. The GR-38 runs in the southern portion of the peninsula and the GR-38A runs in the middle.

In Greek mythology, Mount Pelion (which took its name from the mythical king Peleus, father of Achilles) was the homeland of Chiron the Centaur, tutor of many ancient Greek heroes, such as Jason, Achilles, Theseus and Heracles. It was in Mount Pelion, near Chiron's cave, that the marriage of Thetis and Peleus took place. The uninvited goddess Eris, to take revenge for having been kept outside the party, brought a golden apple with the inscription "To the Fairest". The dispute that then arose between the goddesses Hera, Aphrodite and Athene resulted in events leading to the Trojan War. When the giants Otus and Ephialtes attempted to storm Olympus, they piled Mount Pelion upon Mount Ossa.

The mountain is thickly forested, both deciduous and perennial forests, mainly of beech, oak, maple and chestnut trees, with plane tree groves surrounding places with water. Pelion is considered one of the most beautiful mountains in Greece and is a popular tourist attraction throughout the year: hiking trails and stone paths give access to springs, coves and numerous beaches, sandy or pebbly, set among lusciously green slopes. Pelion is an amply watered mountain, with an abundance of springs, gorges, streams and rivulets, with many streams routed in carved-stone artificial beds to bring the water to the villages and their thriving orchards. The higher elevations of the mountain receive enough snowfall so as to host skiing facilities that operate from Christmas to Easter.