Ruokolahti (Finnish: [ˈruo̯koˌlɑhti]; Swedish: Ruokolax;[6] literally translated the "Reed Bay") 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 (470.99 sq mi) of which 23% is water.

[7] The famous sniper Simo Häyhä lived in Ruokolahti for 57 years after the 1939–40 Winter War.

The coat of arms was designed by Gustaf von Numers and was confirmed for use on September 11, 1951.