Karl Werner Aspenström (13 November 1918 – 25 January 1997) was a Swedish poet.

Born at Norrbärke, he was a member of the Swedish Academy, where he held Seat 12 from 1981 to 1997.

Following his breakthrough in 1949 with Snölegend ("Snow legend") he was considered one of the leading 20th-century Swedish poets, and his poetry has often been compared to the works of the Nobel Prize laureates Harry Martinson and Tomas Tranströmer.

He was a friend of Stig Dagerman.

This article about a Swedish writer or poet is a stub.