Who was the first woman to win the calendar-year Grand Slam in singles?

Maureen Connolly was the first woman to win the calendar-year Grand Slam in singles. Known as “Little Mo,” the American achieved the feat in 1953 by winning the Australian, French, Wimbledon and U.S. championships in one season.

Connolly completed the sweep at the U.S. National Championships on September 7, 1953, defeating Doris Hart 6–2, 6–4 in the final. She was only 18, yet she had already become one of the dominant players in women’s tennis. Her 1953 season included victories over several established opponents and extended a remarkable run of major success.

Her achievement followed Don Budge’s 1938 men’s Grand Slam and preceded Margaret Court’s 1970 women’s sweep and Steffi Graf’s 1988 victory. Connolly won nine major singles titles overall, but her career was cut short after a 1954 horse-riding accident severely injured her leg. That is why later players, rather than Connolly, accumulated more major titles.