Lennart Bergelin (10 June 1925, Alingsås – 4 November 2008, Stockholm) was a Swedish tennis player and coach. As a player, for AIK, Bergelin won nine Swedish championship singles titles between 1945 and 1955, and the French Open doubles title in 1948. Bergelin is best known for his work with Björn Borg, whom he trained between 1971 and 1983, helping him to win 11 Grand Slam tournaments. Bergelin also captained Sweden to its first Davis Cup title.
During a ten-year period, between 1946 and 1955, Bergelin was ranked among the top 10 amateur players in the world. He won 20 national championships (9 singles and 11 doubles) and became the first Swedish player ever to win a grand slam, as he and Jaroslav Drobný won the French doubles championship in 1948. Bergelin played 89 Davis Cup matches representing Sweden and won 63 of these. He played the last DC game, at the age of 40, together with Jan-Erik Lundqvist. Between 1971 and 1976, Bergelin captained the Swedish DC team and in 1975 he led them to victory as they defeated Czechoslovakia in the finals.
Bergelin was awarded the Svenska Dagbladet Gold Medal in 1950.
Peter Bengtsson, a spokesman for the Swedish Tennis Association, said Bergelin died from heart failure at a Stockholm hospital.