CPCO is the professional association for principals and vice-principals in the Ontario Catholic school system. CPCO also welcomes associate members from other organizations, provinces and countries around the world.

CPCO members receive a number of services including legal services for matters relating to their responsibilities, legal telephone advice, Long Term Disability insurance in a provincial group benefits plan, online and print communications, professional development training and e-learning opportunities, a communications network with other members, advocacy for members' issues and for Catholic education and membership in the Canadian Association of Principals.

CPCO meets regularly with partners in Catholic education including the Ontario Ministry of Education, the Institute for Catholic Education, the Ontario Catholic School Trustees' Association, the Ontario Catholic Supervisory Officers' Association, the English Catholic Council of Directors of Education, the Ontario Conference of Catholic Bishops, the Ontario English Catholic Teachers' Association, the Catholic Curriculum Delivery Organization, the Catholic Curriculum Corporation, the Eastern Ontario Catholic Curriculum Consortium, the Northern Ontario Catholic Curriculum Consortium, the Ontario College of Teachers and the Ontario Institute for Studies in Education.