Lake Volvi is located in the root of the Chalkidiki peninsula, in the Thessaloniki regional unit. Lake Volvi is the second largest lake in Greece. It is about 12 miles (19 km) in length, and 6 or 8 miles (9.7 or 12.9 km) wide. The area is 68 km² and the depth is 20 m. It is located east of Lake Koronia (Lake Lagkada).
The new Via Egnatia highway runs along the northern shore of the lake, while the ancient road ran along its southern one. On its east the narrow valley of Rentina, also known as the "Macedonian Tempe". The municipalities of Volvi and Langadas have a shore on the lake.
About a million years ago, Lake Volvi along with Lake Koronia and the entire Mygdonia was a huge lake.