Elassona (; older form: Elasson Ἐλασσών) is a town and a municipality in the Larissa regional unit in Greece. During antiquity Elassona was called Oloosson - Ὀλοοσσών and was a town of the ancient "Perrhaebi", known today as Thessaly. It is situated at the foot of Mount Olympus. Elassona is bypassed by the GR-3 (Larissa - Kozani - Florina).