Luumäki (Finnish pronunciation: [ˈluːˌmæki]) is a municipality of Finland. Its seat is in Taavetti. It is located in the province of Southern Finland and is part of the South Karelia region. The municipality has a population of 4,529
(31 March 2021) and covers an area of 859.83 square kilometres (331.98 sq mi) of
which 109.77 km² (42.38 sq mi)
is water. The population density is
6.04 inhabitants per square kilometre (15.6/sq mi). The municipality is unilingually Finnish.