St. Augustine Catholic High School (Ontario)

St. Augustine Catholic High School () is a high school in Markham, Ontario, Canada. It is a technologically-oriented school, is part of the York Catholic District School Board, and opened in 2001. As of September 2025, it had an enrolment of 1705 students and 92 faculty members. In the Fraser Institute's Report Card on Ontario’s Secondary Schools 2025, the school was ranked 6th out of 746 secondary schools in Ontario with an overall rating of 9.6 out of 10.

Despite its short history, St. Augustine CHS has earned itself a distinguished reputation in the York Catholic District School Board as a strong academic institution, earning high grades in the grade 9 EQAO mathematics and the grade 10 OSSLT. It offers many different special programs that set it apart from other high schools in Ontario, featuring programs like a Specialist High Skills Major (SHSM) program and the unique STREAM Focus program. The St. Augustine CHS STREAM Focus program is an inter-disciplinary approach to inquiry and problem-based learning. It incorporates real-world challenges and the engineering design process to foster critical thinking, creativity, collaboration, and communication skills guided by the traditional principles of Catholic social teachings.