Kymmenegård County (Swedish: Kymmenegårds län, Finnish: Kymenkartanon lääni) was a county of Sweden 1775-1809 and province of Grand Duchy of Finland 1809-1831.
The county was created in 1775 by dividing the Savolax and Kymmenegård County (Swedish: Savolax och Kymmenegårds län, Finnish: Savonlinnan ja Kymenkartanon lääni) into two parts: Savolax and Karelia County and Kymmenegård County. Residence city was Heinola.
By the Treaty of Fredrikshamn in 1809 Sweden ceded all its territories in Finland, east of the Torne River, to Russia. Kymmenegård Province was succeeded in 1831 by the Mikkeli Province in the autonomic Grand Duchy of Finland. Minor parts of province were merged to Uusimaa Province.