The company was established as Imagexcel in the early 1980s and developed more than fifteen games under that name, including Quarantine, which was published by GameTek in 1994.

Rod Humble, as GameTek's executive producer, initially wrote a script titled Bloods that revolved around gang warfare.

[3] On 9 March 1995, the publisher announced its acquisition of Imagexcel's assets through a newly founded subsidiary, Alternative Reality Technologies.

[11] At the same time, Take-Two announced that Rockstar Toronto was working on a video game adaptation of the 1979 film The Warriors.

[15][16] After The Warriors, Rockstar Toronto developed further ports: It brought Manhunt 2 and Bully: Scholarship Edition to the Wii,[17][18] and Grand Theft Auto IV, Grand Theft Auto: Episodes from Liberty City, and Max Payne 3 to Windows.

The port was delayed to April 2015, which the studio attributed to optimizations and the integration of a built-in video editor, which is exclusive to this release.

[28][29] On 24 December 2020, CA$66,000 worth of newly delivered computer equipment and accessories were stolen from Rockstar Toronto's offices.