Mörrumsån is a river in Blekinge County and Kronoberg County, Sweden. It is roughly 185 km long, with its tributary in the lake Asnen, from which it flows south, into the Baltic Sea. The river is known among fishing enthusiasts around the world, because of the salmon fishing that is considered to be among the best in Sweden. The most prominent villages where the river flows through are Mörrum and Svängsta, both located in Karlshamn Municipality.