[1] As a part of the sale, the Majors identity was returned to St. Michael's College, allowing the team to move forward under the fan-selected "Steelheads" moniker.

[2] The Steelheads struggled in their first season in 2012–13 finishing last in the OHL Central division and eighth overall in the Eastern Conference before losing to the Belleville Bulls in six games in the first round.

In the 2013–14 season the Steelheads again finished last in the Central division and eighth in the Eastern Conference, this time being swept by the number one ranked Oshawa Generals in four games in the first round of the 2014 OHL playoffs.

In 2015–16, thanks to strong performances by a trio of top 2016 NHL Entry Draft picks (Alexander Nylander, Michael McLeod, Nathan Bastian) the Steelheads finished above .500 for the first time and ended the season in seventh in the Eastern Conference standings,(fourth in their division).

In the Eastern Conference Finals the Steelheads swept the Peterborough Petes in four games to win their first Bobby Orr Trophy in franchise history.

[citation needed] In 2017–18, Mississauga returned to the bottom of the Eastern Conference ending the season in seventh place (fourth in the Central division).

In 2018–19, Mississauga was the best team of a weak bottom half of the OHL Eastern Conference finishing in fifth place but 20 points back of Sudbury in fourth.