Sven Bert Jonas Karlsson (born 11 March 1971) is a Swedish actor and author.

He won a Guldbagge Award for Best Actor in 2004 for the movie Details.

He published his first book, a collection of short stories, in 2007.

He wrote three short novels that were translated into English: The Room, The Invoice, and The Circus.

[1] His writing often features weird characters and Kafkaesque surrealism.