Treliving, 56, had been with the Leafs since 2023, who have yet to go further than the second round of the Stanley Cup Playoffs (2024) during his tenure.
The team is currently sitting third-from-last in the Eastern Conference with a 31-30-13 record and are set to miss the playoffs for the first time since the 2015-2016 season.
The most notable moves during Treliving's tenure as the Maple Leafs GM include the blockbuster Mitch Marner trade that eventually sent him to the Vegas Golden Knights and the hiring of Craig Berube to replace Sheldon Keefe, who Treliving fired during the 2023-2024 season.
Toronto haven't won a Stanley Cup Finals since 1967.
Treliving had previously been the GM of the Calgary Flames for nine seasons, never once making it past the second round of the Stanley Cup Playoffs.