The 2018 Overwatch League season was the inaugural season for the Overwatch League, an esports league based on the video game Overwatch which began on January 10, 2018. Regular season play continued through June 16, 2018, while post-season play ran from July 11–28, 2018. The London Spitfire won the Grand Finals over the Philadelphia Fusion to become the League champions, with the Spitfire's Park "Profit" Jun-young named the Finals MVP. An All-Star Weekend was held following the post-season from August 25–26, 2018.

The season's format and schedule were announced in November 2017. The inaugural regular season ran from January 10 to June 17, 2018, broken out into four stages. Each stage lasted five weeks, with a one-week break between each stages. Each regular season week featured twelve games, three matches per day from Wednesday to Saturday, with each team having played in two games that week. During stages one and two of season one, at the end of each stage, the top three teams across both divisions, based on their standings in that stage, played a final set of matches to win a US$100,000 prize with the runner-up taking a US$25,000 prize. As of season one stage three, four teams made each stage playoff. The #1 seed chose their opponent in the first round between the remaining three qualified teams. These matches are played on the final day of the stage.^[1][2]

The season's free agency signing window opened on January 22, 2018, and closed on April 3, 2018 (the start of Stage 3). During this period, teams could sign any eligible free agent player or make trades with other teams. Any player on a new team contract before the start of Stage 2 on February 21, 2018, was eligible to play during Stage 2. Otherwise, they had to wait until the start of Stage 3. After April 3, team rosters could not be changed until after the completion of the post-season games.^[3]

The post-season playoffs were held over three weeks in July 2018. It was a single-elimination playoff featuring 6 teams: each division leader, and the next top four teams from both divisions, with their position seeded by their standings.^[1] The Grand Finals were held on July 26 and 27, 2018.

All matches in the inaugural season (except for the Grand Finals) were played at the 350-seat Blizzard Arena, located on the former soundstage for The Tonight Show Starring Johnny Carson in Burbank, California.^[4] Games were broadcast on the Overwatch League's website and through Major League Gaming (owned by Blizzard), and by third-party broadcaster Twitch. The Grand Finals were played at Barclays Center in New York City, where all 11,000 seats available were sold out for both days of the event.^[5]

Pre-season matches were held from December 6 to 8, 2017. Pre-season matches are exhibition only, and do not count towards the regular season standings. The Philadelphia Fusion had to pull out of pre-season play just before these events, citing "player logistics issues".^[6]

The Overwatch League began the season with a two-year exclusive contract for Overwatch League broadcasting. Its debut week held an overall peak of 441,000 concurrent viewers on its three Twitch channels, with 392,000 English, 65,000 Korean, and 11,500 French viewers.^[7] Through the season, average online viewership ran between 80,000 and 170,000.^[5] At least 310,000 viewers watched the final match of the Grand Finals.^[5]

On the first day of the season playoffs, Disney and Blizzard announced a multi-year partnership that would bring the league and other professional Overwatch competitive events to ESPN, Disney XD, and ABC, starting with the playoffs and throughout all of the following season.^[8] Nielsen ratings for the Grand Finals include a 0.18 rating (approximately 218,000 households) for the Friday match airing on ESPN, while the recap of the series airing on ABC on the Sunday after the event had a 0.3 rating (approximately 359,000 households).^[9] Blizzard estimated that over a million people were watching the Grand Finals at any time, between broadcast and streaming formats, with a total viewership of over 10.8 million.^[10][11]

A team's standing is based on both their overall match win–loss record, with ties broken by their overall round record.

At the end of Stages 1 and 2, the top three teams overall in the current stage, regardless of division, made the stage playoffs. The first seeded team earned a bye, with the second and third seeded teams playing a best-of-5 series to advance to the stage finals. Beginning with Stage 3 of the 2018 season, Blizzard announced changes to the Stage Playoff format. Introduced was a four-team Stage playoffs going forward, so that both teams in the final match will have played the same number of games on that day. The first seed has the option of selecting their opponent for the first round and has home team advantage, with the remaining two teams assigned based on seed ranking. These stage playoffs have no effect on overall standings and are only for bonus prize money.

Teams' overall standings were used for placement in the post-season playoffs. The top team of each division received an automatic bye, while the next top four teams, regardless of division, filled in the remaining tournament slots.

After the regular season, the New York Excelsior and the Los Angeles Valiant finished atop their respective divisions, earning first-round byes. The next four remaining teams, Boston Uprising, Los Angeles Gladiators, London Spitfire, and Philadelphia Fusion, were seeded according to regular season record, regardless of division. The third-seeded Uprising played the sixth-seeded Fusion, while the fourth-seeded Gladiators played the fifth-seeded Spitfire. Each series was a best of 3 matches (each match was best of 5 maps). The winners of the two semifinal matches advanced to the Grand Finals, which took place at Barclays Center in Brooklyn, New York from July 27–28.^[19][20]

From JJonak's MVP award, Blizzard created a special cosmetic skin for Zenyatta, the character that JJonak most frequently played, which was offered to viewers and players during the 2019 season.^[21]

The 2018 Overwatch League All-Star Game was the Overwatch League's first edition of an all-star game that involved the All-Star players of the league. The game was played on August 26, 2018, and was the culmination of the league's All-Star Weekend, a two-day event that consisted of Lúcioball, Mystery Heroes, a Widowmaker 1v1 tournament, Talent Takedown, and Lockout Elimination. All of the events were played at Blizzard Arena in Burbank, California. The game was televised by Disney XD and ESPN3 and streamed live on Twitch.^[22][23]

Teams in the first season competed for a total prize pool of US$3.5 million across regular season play, stage finals, and playoffs.^[2] By league rules, at least 50% of these winnings were split among the team's members, the remaining going to the team's owner.