Åsnen is a large lake in southern Småland, Sweden, roughly 150 km² in size. The river Mörrumsån flows south from Åsnen into the Baltic Sea. The lake lies south of Alvesta and Växjö and northwest of Tingsryd and is the second-largest lake in Smålands, after Bolmen. Approximately 19 km² of the lake's area is occupied by small islands.