Methydrio (, before 1927: Νεμνίτσα - Nemnitsa) is a village in the municipal unit of Vytina, Arcadia, Greece. In 2001, it had a population of 14. It sits at 1,060 m above sea level, at the foot of the Mainalo mountains. It is 4 km south of Vytina. It was named after the ancient city Methydrion, the remains of which have been discovered near the village.