Alliance United FC

Alliance United joined the men's division of League1 Ontario for the 2018 season. They played their inaugural match on April 29, 2018 against North Mississauga SC at home, which they lost by a score of 1–0. They finished in 7th place in their debut season. They improved to a 3rd-place finish in the 2019 season, but had a very poor showing in the playoffs where they lost 15–0 to FC London on aggregate in the semi-finals over the two-game series, due to being unable to field many of their best players, who missed the series due to college and university commitments, thereby having to rely on many youth players instead.

In 2019, the club added a team in the League1 Ontario women's division. In their debut season, they finished in a three-way tie for fifth, but did not play in 2020 or 2021 due to the COVID-19 pandemic. In their return in 2022, they finished 6th in the regular season, but advanced to the Championship Final in the playoffs, where they were defeated by NDC Ontario. In addition, they advanced to the League1 Canada Women's Interprovincial Championship for 2022, as NDC Ontario was unable to compete due to player unavailability, where they finished in 3rd place, following a defeat to PLSQ side AS Laval in a penalty shootout in the semi-finals, before defeating League1 British Columbia side Varsity FC in the third-place match in another penalty shootout. In 2023, after finishing 4th in the regular season, they won the women's league championship defeating NDC Ontario in the playoff final.

In 2023, they formed an affiliation with Canadian Premier League club York United FC, which enables York United to send players to Alliance on short-term loans. On July 29, 2023, they recorded their largest victory, defeating Unionville Milliken SC by a score of 13-1.