International Tennis Federation in the context of "1999 ATP Tour"

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 Grand Slams or 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 Davis Cup is the premier international team event in men's tennis. It is organised by the International Tennis Federation (ITF) and contested annually between teams from over 150 competing countries, making it the world's largest annual team sporting competition. It is described by the organisers as the "World Cup of Tennis" and the winners are referred to as the world champions. The competition began in 1900 as a challenge between Great Britain and the United States. Initially titled the International Lawn Tennis Challenge, it soon became known metonymically after the trophy donated by Dwight F. Davis; the name was officially changed after Davis' death in 1945. By 2023 155 nations entered teams into the competition.

The most successful country over the history of the competition is the United States (winning 32 titles and finishing as runners-up 29 times). The most recent champions are Italy, who beat Spain to win their fourth title (and third consecutive one) in 2025.

The Billie Jean King Cup, abbreviated as the BJK Cup, is the premier international team competition in women's tennis, launched as the Federation Cup in 1963 to celebrate the 50th anniversary of the International Tennis Federation (ITF). The name was changed to the Fed Cup in 1995, and changed again in September 2020 in honor of former World No. 1 Billie Jean King. The Billie Jean King Cup is the world's largest annual women's international team sports competition in terms of the number of nations that compete. The current chair is Katrina Adams.

The men's equivalent of the Billie Jean King Cup is the Davis Cup, and the Czech Republic, Australia, Russia, Italy and the United States are the only countries to have won both Cups in the same year.

Tennis was part of the Summer Olympic Games program from the inaugural 1896 Summer Olympics, but was dropped after the 1924 Summer Olympics due to disputes between the International Lawn Tennis Federation and the International Olympic Committee over how to define amateur players. After two appearances as a demonstration sport in 1968 and 1984 (with a U-21 age limit), it returned as a full medal sport at the 1988 Summer Olympics open for all players regardless of their age and status and has been played at every summer Games since then.