Assumption Catholic Secondary was the first Catholic secondary school in Halton.  It opened in 1977 at 802 Drury Lane (the current site of the HCDSB Administration offices). In 1980 Assumption moved to it current site on Woodward Avenue.

Assumption Catholic Secondary School is a faith-centered learning community that fosters excellence within the individual, promoting academics and citizenship through the living of Christian values.

Assumption Catholic Secondary School, together with home, church, and community, values the uniqueness of each person and is dedicated to lifelong learning, personal development, and spiritual growth.

Learning is a co-operative endeavour shared amongst teachers, students and parents. The student is the focal point of Catholic Education. Assumption students are encouraged to work and learn to their maximum potential.

Our school is dedicated to academic excellence, the development of each individual's interests and talents and the nurturing of the Roman Catholic faith. Students are taught to think critically, work independently, communicate effectively and show respect for themselves, for others and for the environment.

By accepting the challenge of education now, our students will be prepared to meet the future with faith, confidence and a strong sense of their own self-worth. The staff of Assumption Catholic Secondary School, in partnership with home and church, is dedicated to helping our students respond to this challenge by helping them discover the strengths and talents inherent in each and every one of them.