Bobby Jones is the only golfer to win all four major championships in a single calendar year, accomplishing the feat in 1930.
Jones won the British Amateur at St Andrews in May, the British Open at Royal Liverpool in June, the U.S. Open in July, and the U.S. Amateur at Merion in September. This was the Grand Slam as the major championships were defined in his era. The modern Masters did not yet exist; it began in 1934.
Jones was an amateur throughout this achievement, making the accomplishment even more unusual. He won 13 major championships overall before retiring from competitive golf at age 28 after the 1930 season. His success helped establish him as one of the defining figures in golf history.
A common mistake is to count the Masters among the four tournaments Jones won. That is impossible because the Masters had not been founded. Modern players have won four majors across their careers, and some have held all four titles at once across different seasons, but no one has matched Jones’s calendar-year sweep.