Baron Bo Gustaf Bertelsson Carpelan (25 October 1926 – 11 February 2011) was a Finnish poet and author. He published his first book of poems in 1946, and received his Ph.D. in 1960. Carpelan, who wrote in Swedish, composed numerous books of verse, as well as several novels and short stories.
In 1997, he won the Swedish Academy Nordic Prize, known as the 'little Nobel'. He was the first person to have received the Finlandia Prize twice (in 1993 and 2005). He won the 2006 European Prize for Literature. His poem, Winter was Hard, was set to music by composer Aulis Sallinen. He also wrote the libretto for Erik Bergman's only opera, Det sjungande trädet.
Carpelan died of cancer on 11 February 2011. He is buried in the Hietaniemi Cemetery in Helsinki. He was a member of the Finnish noble family Carpelan.
Carpelan went to Svenska normallyceum i Helsingfors and then studied history of literature at University of Helsinki. He became Doctor of Philosophy in 1960.