Ierissos is a small town on the east coast of the Akti peninsula in Chalkidiki, Greece. It is located 115 km from Thessaloniki, and 10 km from the border of the Autonomous Monastic State of the Holy Mountain, or Mount Athos. It is the site of Ancient city and former bishopric Hierissus, and as such remains a Latin Catholic titular see. Ferries run from Ierissos to the east coast of Mount Athos.