The municipality has a population of 2,058 (31 December 2024)[6] and covers an area of 746.59 square kilometres (288.26 sq mi) of which 281.2 km2 (108.6 sq mi) is water.

[1] The population density is 4.42 inhabitants per square kilometre (11.4/sq mi).

Neighbour municipalities: Joutsa, Kangasniemi, Mikkeli, Mäntyharju and Pertunmaa.

Most islands, though, are only inhabited during the summer holidays, when holidaymakers come mainly from Southern Finland and double the population of Hirvensalmi.

Hirvenlahti, Hirvensalmi, Hämeenmäki, Kekkola, Kilkki, Kissakoski, Kotkatvesi, Kuitula, Lahnaniemi, Lelkola, Malvaniemi, Monikkala, Noitti, Pääskynsaari, Suonsalmi, Syväsmäki, Vahvamäki, Vahvaselkä, and Väisälä.