Rod Laver is the only male tennis player to win a calendar-year Grand Slam twice. The Australian left-hander achieved the feat in 1962 and repeated it in 1969, winning the Australian, French, Wimbledon, and US championships in the same calendar year each time.
His first Grand Slam came during the amateur era. Laver won the four major singles titles in 1962 before turning professional, which meant he was barred from competing in the traditional amateur majors for several years. His second came in 1969, after the Open Era began and the major tournaments became available to leading professionals.
The 1969 achievement is especially notable because it brought together the strongest professional field of the period. Laver won all four finals and finished the season with 18 tournament titles and a 106–16 singles record. He also won the 1967 professional Grand Slam, a related but separate achievement involving the major professional tournaments of that era.
Don Budge was the first man to complete a calendar-year Grand Slam, doing so in 1938, but he did it once. Novak Djokovic has completed a career Grand Slam and came close to a calendar-year sweep, but he has not won all four majors in the same year.