Thoknia (Greek: Θωκνία) is a village in the municipality of Megalopoli, Arcadia, Greece. It is situated near the confluence of the rivers Alfeios and Elissonas, at about 360 m elevation. It was named after the ancient Arcadian city Thocnia, that was located in the area. Thoknia is 2 km east of Kato Karyes, 3 km southeast of Kyparissia, 3 km southwest of Plaka and 5 km northwest of Megalopoli. Thoknia had a population of 49 in 2001. The village is surrounded by open-pit lignite mines.