The club was founded in 1976 to serve the communities of
Unionville and
Milliken in
Ontario. Originally a youth soccer club, the team added semi-professional teams in
League1 Ontario (now the
Ontario Premier League in the women's division in 2017, followed by a men's team in 2018. In their inaugural season, the women's team finished in 4th place. Unionville announced that their club would go with a fully professional model, as opposed to an amateur or semi-professional approach, becoming the second fully professional team in the league, after
Toronto FC III. The men's team was formed through a partnership with
York Region Shooters, who played in the
Canadian Soccer League until 2017, to form a professional club in L1O to begin in 2018, created through the relationship of Shooters' owner
Tony De Thomasis and UMSC coach
Filipe Bento. They played their inaugural match on April 29, 2018 against
Windsor TFC, which resulted in a 3–1 victory. In 2022, the women's reserve team won the League1 Ontario Reserve Division. In 2025, the men's team won the League1 Ontario Championship, earning promotion to the League1 Premier division for 2026. == Seasons ==