Twelve Overwatch League teams competed in the inaugural 2018 season. The league launched as Blizzard’s franchised global esports competition, with each team representing a major city rather than a traditional national league.
The inaugural lineup included the Boston Uprising, Dallas Fuel, Florida Mayhem, Houston Outlaws, London Spitfire, Los Angeles Gladiators, Los Angeles Valiant, New York Excelsior, Philadelphia Fusion, San Francisco Shock, Seoul Dynasty, and Shanghai Dragons. These teams played the regular season from January 10 through June 17, 2018, across four stages.
The twelve-team figure applies specifically to the first season. The league expanded to 20 teams for the 2019 season, adding franchises such as Atlanta Reign, Chengdu Hunters, Guangzhou Charge, Hangzhou Spark, Paris Eternal, Toronto Defiant, Vancouver Titans, and Washington Justice. That expansion is the main reason later Overwatch League totals can be mistakenly applied to the inaugural season.