Ierissos (Greek: Ιερισσός) is a small town on the east coast of the Akti peninsula in Chalkidiki, Greece.

It is the site of Ancient city and former bishopric Hierissus, and as such remains a Latin Catholic titular see.

During that time the Venetians, starting from Cassandreia, landed on the coastline of Ierissos, burnt down the settlement (by then only a large village) and its surroundings and (on departure) set alight the castle and five towers.

In 1821 Ierissos took part in the Greek War of Independence and during the repression the village was burnt down by the Turks and a large number of residents killed.

After the earthquake the new Ierissos was built in its current position, a little north west of the ancient city.