Björn Rune Borg is a Swedish former professional tennis player. He was ranked as the world No. 1 in men's singles by the Association of Tennis Professionals (ATP) for 109 weeks. Borg won 66 singles titles during his career, including eleven majors: six at the French Open and five consecutively at Wimbledon. Borg was ATP Player of the Year from 1976 to 1980, the year-end No. 1 in the ATP rankings in 1979 and 1980, and the ITF World Champion from 1978 to 1980.
A teenage sensation at the start of his career, Borg experienced unprecedented stardom and consistent success that helped propel the rising popularity of tennis during the 1970s. Between 1974 and 1981, Borg claimed 11 major singles titles, the most by any man in the Open Era up to that point. His rivalries with Jimmy Connors and John McEnroe became cultural touchstones beyond the world of tennis, with the latter rivalry peaking at the 1980 Wimbledon final, considered one of the greatest matches ever played. Following defeats to McEnroe in the 1981 Wimbledon and US Open finals, Borg unexpectedly retired from tennis at the age of 25.