In the mid-1980's, after provincial funding for Ontario Catholic schools was extended to the end of high school,  there began a rapid increase in the number of Catholic secondary schools. Concerned about the "Catholicity" of  the secondary schools, the Ontario Conference of  Catholic Bishops called for the presence of Chaplains in  all the secondary schools and "the upgrading of  chaplaincy work into a full ministry of pastoral service or  care." (This Moment of Promise; and New Directions.)

As more and more Chaplains were hired to serve the secondary schools, including many lay women and men, a need quickly arose to achieve some definition of what the role of the school Chaplain should be, not to mention the provision of a support network for those taking on this task of ministry. In November, 1987, school Chaplains from all over Ontario gathered together for the first time. There were many questions and problems being faced by Chaplains in terms of how they were being understood and accepted, the time allotments they were assigned, etc. It was also clear that collectively the Chaplains shared a great wealth of experience, credentials and dedication.

A year later, in October, 1988, CSCO (Catholic School Chaplains of Ontario) was incorporated and its constitution ratified. The new executive of CSCO began the work of establishing contact with the other provincial organizations which were "partners in Catholic Education." The process of networking among school Chaplains was undertaken, a newsletter was started, and the work of giving a clearer definition to Chaplaincy was begun.

As we move forward into the new millennium, CSCO continues the work of promoting a better understanding of School Chaplaincy and of supporting School Chaplaincy Leaders in their work. CSCO now counts among its members over 230 Chaplaincy Leaders  from high schools in all corners of the province of Ontario, as well as other members from outside the school system who have an interest in the future of this important form of pastoral ministry.