Kymenlaakso is a region in Finland. As of November 2013, there were over 180,000 people living there. Neighbouring regions are Uusimaa, Päijänne Tavastia, Southern Savonia and South Karelia.
Municipalities in the region are Hamina, Iitti, Kotka, Kouvola, Miehikkälä, Pyhtää and Virolahti. Kymenlaakso was one most earliest industrialized areas in Finland, since around the 1800s.