Grand Slam (tennis)

The Grand Slam in tennis is the achievement of winning all four major championships in one discipline in a calendar year. In doubles, a Grand Slam may be achieved as a team or as an individual with different partners. Winning all four major championships consecutively but not within the same calendar year is referred to as a "non-calendar-year Grand Slam", while winning the four majors at any point during the course of a career is known as a "Career Grand Slam".

The term Grand Slam is also attributed to the Grand Slam tournaments, referred to as Majors, and they are the world's four most important annual professional tennis tournaments. They offer the most ranking points, prize money, public and media attention, the greatest strength and size of the field and, in recent years, the longest matches for men (best of five sets, best of three for the women). The tournaments are overseen by the International Tennis Federation (ITF), rather than the separate men's and women's tour organizing bodies, the Association of Tennis Professionals (ATP) and Women's Tennis Association (WTA), but both the ATP and WTA award ranking points based on players' performances in them.

The Grand Slam tournaments are the Australian Open in January, the French Open in late May to early June, Wimbledon in late June to early July, and the US Open in late August to early September, with each played over two weeks. The Australian and the US tournaments are played on hard courts, the French on clay court, and Wimbledon on grass court. Wimbledon is the oldest tournament, founded in 1877, followed by the US in 1881, the French in 1891 (major in 1925), and the Australian in 1905, but it was not until 1923 that all four were designated as "Official Championships".