Lake Mjøsa lies directly below Lillehammer, its northern tip touching the town's waterfront. The lake is 117 kilometres long and up to 15 kilometres wide, with the towns of Gjøvik on the western shore and Hamar to the south as the other main settlements along its banks. The Skibladner paddle steamer connects these towns in summer, and the E6 highway runs along the eastern shore.
For visitors in Lillehammer, the lake is primarily a setting — the view from Storgata and the upper town looks south over the water toward the distant hills of Hedmark. The lakefront promenade is pleasant for an evening walk. The lake also has fishing (perch, pike, and trout) in summer and ice fishing in winter. On cold winters when the lake freezes completely, skating tours across the ice attract serious winter sport enthusiasts.