Oktonia is a hillside village found in the east-central area of Euboea Island, belonging to the municipality of Kymi-Aliveri, Greece. Located near the lower side of the Gulf of Kymi, the village is composed of four settlements: Alonia, Panochori, Katochori and Panagia, covering a large area. It is 145 km from Athens, a distance covered in about 2.5 hours by car. According to the census of 2021, the community of Oktonia, which also includes the villages Agios Merkourios and Mourteri, has 519 permanent inhabitants.