Lars Gunnar "Lasse" Lönndahl (born 19 August 1928) is a Swedish singer and actor, born in Stockholm. He is considered the most well-known Swedish singer of the 1950s and 1960s with nicknames including "The Swedish Frank Sinatra" and "World's Oldest Teenager". Even though by the mid-1970s his career had slowed down, he is still considered arguably Sweden's most popular singer of all time and was long a very popular figure in media.