Iisalmi is a town and municipality situated in the North Savo region of Finland. Located approximately 87 kilometres north of Kuopio and south of Kajaani, it serves as an administrative center within this northern landscape. The municipality covers a total area of 872.20 square kilometres, which includes significant water bodies comprising 109.22 square kilometres of the total surface.

The area traces its origins to 1627 when the parish of Iisalmi was established around the local church. The town gained official status on October 20, 1891. Historically, the Koljonvirta strait served as a battlefield during Swedish rule, witnessing one of Sweden's last victories on Finnish soil before the region was surrendered to Russia in 1809.

The landscape is defined by 111 lakes, including Onkivesi and Haapajärvi. Notable sites include the Gustav Adolf Church, consecrated in 1780, and the Koljonvirta bridge, a historic Napoleonic war site. The town also features the Hanhenlento Zoo and the Olvi brewery museum, reflecting its industrial heritage and natural surroundings.

Iisalmi is known for cultural events such as the Oluset music festival and Limuset, an alcohol-free counterpart. The local cuisine includes Muurinpohjalettu, a traditional pancake. Visitors are drawn to the world's smallest restaurant, Kuappi, and the town's vibrant arts scene, which includes the humorous country-rock band Halavatun Papat and composer Joonas Kokkonen.

The population was 20,205 as of 31 December 2025. The economy relies on export industries and education, anchored by companies like Olvi brewery, Genelec, and Normet. Transport access includes a railway station on the electrified line to Oulu and bus connections along highway 5, with nearby airports in Kuopio and Kajaani.