On September 7, 2018, Blizzard Entertainment announced that OverActive Media Group had purchased a slot for a Toronto-based franchise. On the same day, Splyce announced that they would be joining working with OAM to form and operate the unnamed Toronto team with Chris Overholt of OAM and Marty Strenczewilk of Splyce as the team owners. Former CEO of the Canadian Olympic Committee Chris Overholt was named the president and CEO of the franchise. "Who could have predicted what is and what this has become globally," Overholt said in an interview. "This thing is not set to explode, it's exploding and I think we're well positioned to take this on in Toronto and Canada." Three days later it was announced that Beom-joon "Bishop" Lee would be the team's head coach. On October 24, 2018, OAM and Splyce officially revealed the branding, name, and staff of the team. Bishop would be joined by General ManagerJaesun "Jae" Won, assistant coachYun "Bubbly" Ho Cho, strategic coach Dongwook "Don" Kim, and analyst Dennis "Barroi" Matz. From October 27, 2018 to November 27, 2018, Toronto Defiant announced their players. envy and Neko were announced as the first two players. Shortly afterwards Ivy and Stellar joined, with Aid and Yakpung following. Finally, RoKy and Asher were announced as the final two members.
Inaugural season
Toronto Defiant's first regular season OWL match was a 3–2 victory against the Houston Outlaws on February 15, 2019. After posting a 5–2 record in Stage 1, the Defiant qualified for the Stage 1 Playoffs, but a 0–3 loss against the Shock eliminated the team in the quarterfinals. The team failed to recreate the success they found in Stage 1 in the following stages, going 2–5, 0–7, and 1–6 in Stages 2, 3, and 4, respectively. A 2–3 loss to the Fusion on August 4 officially eliminated Toronto from postseason contention, and three days later, the team released head coach Lee "Bishop" Beom-joon. Despite numerous roster changes throughout the season, the Defiant finished the season in 17th place overall with an 8–20 record.
Team identity
On October 24, 2018, the franchise name was revealed as the Toronto Defiant; the name "Defiant" was chosen to "represent the strength, character, and resiliency of Toronto." Branding work was done in partnership with the Overwatch League and OverActive’s agency of record Diamond Marketing. The logo and official colors were also released. The logo for Toronto Defiant displays the letter T inscribed in the letter D in the team's colours of red, black, white, and grey.
On February 14, 2019, Overactive Media partnered with Mirage Sport Électronique to launch Toronto Defiant's official academy team in Montreal to compete in Overwatch Contenders. "We are really excited about partnering with Yannick and his team to launch the first pro esports franchise in Quebec," Overholt said in an interview. "Today is about continuing our commitment to growing esports nationwide, and expanding our Toronto Defiant fanbase in Quebec and across Eastern Canada." On February 19, the franchise announced that the team would be known as the Montreal Rebellion.