The archaeological findings at Dimini and Sesklo indicate that the area of ​​Magnesia was already inhabited in the Neolithic period. In the Mycenaean era, its inhabitants were the Magnites, the descendants of Magnes, after whom the region is named.

In ancient times, references in Magnesia were plenty, blending myth and reality. Pelion was thought to be the home of Centaurs, the mythical creatures that were half men and half horses. It is actually said that the wisest of them, Centaur Chiron, was the tutor of both Achilles and Asclepius. Homer mentions that ships from Magnesia, led by Philoctetes, participated in the Trojan War. Also, the famous city of lolkos, from where the Argonauts began to bring the famous "Golden Fleece" from Colchis, belongs to Magnesia.

After the Mycenaean Age, the cities of Magnesia subdued to Thessaly and when they were defeated by Philip II, the father of Alexander the Great, all cities of Magnesia were led to decline. In the 12th century, Almiros becomes an important commercial center of the region, thanks to the settlement of the Venetians and the Genoese. During the Ottoman occupation, the villages of Pelion are introduced to tremendous intellectual and economic prosperity.

Although Magnesia took part in the 1821 Revolution, it was finally united with the Greek State in 1881.