Cardinal Ritter Prep opened its doors on September 6, 1979. Named for Cardinal Joseph Ritter, Archbishop of St. Louis in the mid-1900s, Cardinal Ritter Prep honors its namesake as one of the most prominent and influential church and civic leaders of the century.

In 1977- 1978, a community representative task force was established by the Board of Catholic Education of the St. Louis Archdiocese to study the future existence of a Catholic school in the old Labouré location at in North St. Louis. Arrangements to establish Cardinal Ritter College Prep High School as a co-educational college preparatory high school began in August 1979.

On May 18, 2003, Cardinal Justin Rigali dedicated the new Cardinal Ritter Preparatory High School at 701 N. Spring Avenue, St. Louis. The school opened its doors for students in August 2003.

Cardinal Ritter Prep provides an educational program that prepares students for leadership roles in a multi-ethnic society. Although we are a Catholic high school, our student body represents a wide variety of faiths. The majority of the student body is not Catholic. Our school serves as a magnet, inviting and attracting students who are committed to their education and to becoming the best possible citizen.