Agios Konstantinos is a village in Farsala Municipality, in the regional unit of Larissa, in the region of Thessaly, Greece. Agios Konstantinos lies at 250 m above sea level, 5.7 km from the Pelion mountains. It has 112 inhabitants (2021). The nearest city is Larissa, 27 km to the north. Among the landmarks around are Pherae (25 km), Sesklo (33 km) and Demetrias (40 km). Among the natural features are Cynoscephalae Hills (32 km).

Also written Άγιος Κωνσταντίνος.