Demetrias was established by Demetrius Poliorcetes, King of Macedonia, in 293/92 BC. In 197 BC Romans annexed Demetrias.

To the west of Volos there are the Neolithic settlements of Dimini with a ruined acropolis, walls and two beehive tombs dated between 4000-1200 BC and Sesklo with the remains of the oldest acropolis in Greece (6000 BC), as well as the foundations of a palace and mansions, among the most typical examples of Neolithic civilisation.

During Byzantine empire, emperor Justinian I in 551 fortified Palea hill. In 1423 Ottomans annexed Volos. Volos during the Ottoman empire was a hamlet, build on the hill in Palea district. The hill was fortified with walls. Today just a few parts of the walls can be seen near the Tsalapata building.

After its annexation to Greece from the Ottoman Empire in 1881, it had a population of only 4,900 but rapidly grew within the next 4 decades. Houses were built outside the walls and the main area of Volos by the sea was built up. Merchants, businessmen, craftsmen and sailors moved to Volos from the surrounding area. In the 1920s there was a large influx of refugees in Volos, especially from Ionia, but also from Pontus, Cappadocia and Eastern Thrace. In the 1920 census, Volos had 30,046 inhabitants but according to the 1928 census, its population had grown to 47,892.