Yakym Somko (Ukrainian: Яким Сомко, Polish: Jakim Somko) (born ? in Pereiaslav, died on September 28, 1664), was a Ukrainian Cossack military leader of the Pereyaslav regiment and was the Acting Hetman of Left-bank Ukraine in 1660-1663, during The Ruin. He was first appointed captain of the Pereiaslav regiment in 1654, and became the acting colonel in 1658.