Ruokolahti is a municipality of Finland, situated in south-eastern Finland, in the region of South Karelia. Neighbouring municipalities are Imatra, Lappeenranta, Taipalsaari, Puumala, Sulkava, Punkaharju, Parikkala and Rautjärvi. Ruokolahti covers an area of 1,219.85 square kilometres of which 23% is water.
The municipality has 4,924 inhabitants
, but the population is doubled in summer as holidaymakers occupy the 3,000 summer cottages in the region.
Ruokolahti is known for its natural environment, for example Kummakivi is a balancing rock located at 61° 29' 36.4596" N, 28° 25' 45.5016" E in Ruokolahti and is protected. In the west there is the Lake Saimaa and in the east there are hundreds of smaller lakes. The Salpausselkä ridges run through the area.
The famous sniper Simo Häyhä lived in Ruokolahti for 57 years after the 1939–40 Winter War. He is buried there in the graveyard of Ruokolahti Church.