The Matignon Alumni Association was formed in 1949 and re-activated in the late 1980's as the Friends and Alumni of Matignon High School. In 1995 it was re-organized under the leadership of John C. Rennie '54. At the invitation of the school administration, a Board of Directors was formed from members of the Friends and Alumni and other alumni who had been actively volunteering at the school. A committee began developing by-laws for the association, which were accepted by both the Executive Board and the school administration in December of 1996.
Today the Alumni Association is an integral part of the life of the school with over 8,000 members. Through the Board of Directors and its sub-committees, the Association aims to provide educational, social and financial activities that strengthen the relationship among graduates and support the catholic educational mission of the current school staff and student body.