1926 - Notre Dame Academy opens as an all girls' school owned and operated by the Notre Dame Sisters.

1964 - Archbishop Rummel High School opens as an all boys school operated by the De LaSalle Christian Brothers.

1974 - Notre Dame and Rummel merge to form an Archdiocesan, coed high school – Roncalli High School, named after Pope John XXIII (Angelo Giuseppe Roncalli).

1993 - Roncalli changes it name to Roncalli Catholic High School.

2003 - On July 3, 2003, Roncalli Catholic High School was brought into formal association with Lasallian ministries of the Midwest District of the De LaSalle Christian Brothers.  This association provides opportunities for faculty, staff and students to be enriched by workshops, formation opportunities and youth activities sponsored by the District.