Ascension of Our Lord Secondary School

Ascension of Our Lord Secondary School is located in the City of Mississauga, in Ontario, Canada.

It is part of the Dufferin-Peel Board. It was originally established as a Middle School (Junior High School), but was converted to a Secondary School (High School) in the 1980s. The school building was expanded at that time to accommodate the extra students, and in the 1990s portable classrooms were added and removed as the student population expanded and contracted.

In 2005 the original building was demolished and a new larger structure was built. The facility was opened to students in January 2006.

In 2012, the Fraser Institute named Ascension as one of Ontario's fastest improving schools. Although a Catholic school, it is open to and welcomes students from all religious backgrounds, even providing accommodations for those of other religions.