Kallavesi is a medium-sized lake in Northern Savonia, eastern Finland located around the town of Kuopio. Combined with the lakes Suvasvesi, Juurusvesi–Akonvesi, Muuruvesi, Melavesi, and Riistavesi Kallavesi forms an 890 square kilometres lake system named Iso-Kalla. Kallavesi is the largest lake in the region and the tenth largest lake in the country.