Lars Gunnar Raldo "Lasse" Björn (born 16 December 1931) is a Swedish former ice hockey defenceman who played 217 games for the national team Tre Kronor. He was born in Stockholm, Sweden. He won nine Swedish ice hockey championships with Djurgårdens IF between 1950 and 1963, making him the only player ever to have won that many championships. He participated at nine IIHF World Championship tournaments, winning gold in 1953 and 1957 and three bronze medals. He participated in three Winter Olympics, winning one bronze medal in 1952. He was inducted into the International Ice Hockey Federation Hall of Fame in 1998.
Djurgården has retired number 12 in his honor.
He is the maternal grandfather of retired player Douglas Murray, a Cornell University alumnus who played defense for the San Jose Sharks, Pittsburgh Penguins, and Montreal Canadiens.