There are four major tennis competitions in the world, commonly known as the Grand Slam tournaments. These are:

1. Australian Open: Held annually in Melbourne, Australia, in January.
2. French Open (Roland Garros): Held annually in Paris, France, in May and June.
3. Wimbledon: Held annually in London, England, in June and July.
4. US Open: Held annually in New York City, United States, in August and September.