The Archdiocese of Chicago School System is the largest Catholic school system in the United States. It is the largest private school system in the country. It serves the city of Chicago as well as Cook and Lake Counties, has approximately 70,000 students in its approximately 200 schools. The AOC schools have been the recipient of the greatest number of Blue Ribbon Awards of any school system in the nation. Our Catholic Schools are a living response to the church’s mission and they work with parents/guardians as partners in the academic education and faith development of their children. AOC Catholic Schools are accredited by the Archdiocese and the State of Illinois.