The municipal unit Vilia covers the mountainous northwestern part of Attica, and has a land area of 144.851 km². The main mountain ranges are Cithaeron (1,409 m) in the northwest and Pastra in the northeast. In the west it stretches along the coast of the Alkyonides Gulf, a bay of the Gulf of Corinth. The village Vilia, the largest in the municipal unit, lies in the easternmost part, at the southeastern foot of Cithaeron. Vilia is 6 km south of Erythres, 7 km west of Oinoi, 10 km east of the coastal village Aigosthena, 17 km south of Thebes and 40 km northwest of Athens.