The College was named after St Leo the Great, who was one of the early Popes of the Catholic Church. St Leo famously went forth from Rome, with the cross as his standard and defence to plead with Attila the Hun to spare the eternal city and its people. By the force of his personality, he succeeded where others had failed. After he died in 461 AD, St Leo was honoured for his work with the title of Doctor of the Church.

The year 1983 was a momentous one in the College’s history. By 1983, the Brothers were no longer able to staff the College and so its administration was passed to the Catholic Education Office, Sydney. Upon the departure of the Christian Brothers, the first lay Headmaster was appointed.

The College became co educational, with the first girls enrolling in Year 11 in 1983 and Year 7 in 1984. By 1987 the College had fully completed the integration of co-education. When the newly created Diocese of Broken Bay was formed, the College came under the jurisdiction of the Catholic Schools Office, Broken Bay.

In the 1980s, the College undertook an extensive building program including the creation of the Brother Crohan Library and the Brother Berg Building, incorporating a multi-purpose hall and extensive art and hospitality facilities. In 2002 a new Technology Centre was constructed placing St Leo’s at the forefront of technological learning. The Light of Christ Centre was opened in 2012, providing high quality sporting facilities for the College.

The College completed an extensive $25 million building works program in 2020 including the new Mary MacKillop Centre for Creative and Performing Arts, Technology and Hospitality. The Centre includes a state-of-the-art dance and drama theatre, commercial kitchens, TAS workshops, art gallery, visual art studios, specialty music, orchestra, and band rooms as well as other flexible meeting and learning spaces.

Other upgrades during the staged 10-year building program included renovation of the College’s spiritual heart – the Chapel, refurbishment of the Aquinas Resource Centre with library and cafe, a new College entrance and signage, extensive landscaping, additional outdoor recreation spaces, an extensive classroom furniture and technology upgrade, an extensive refurbishment and technology upgrade of the old ‘C Block’ building including a full refit of the canteen and inclusion of a specialised Dance Studio – and various other improvements.

The completion of the building program was celebrated with a wonderful Rededication ceremony and blessing of the College campus in February 2021 by Bishop Anthony Randazzo together with the entire College community and a number of special guests.

The current St Leo’s community is indebted to the Christian Brothers for the strong Catholic foundation that was established for the College. At present, the College has over 900 students from Years 7–12 and is growing quickly with record Year 7 intakes over the past few years.

As a Catholic, comprehensive, co-educational high school, the College exists to provide the best possible faith, learning and growth environment for the College community. We strive to provide a holistic Catholic education designed to assist each student to achieve their own personal best.