The Ballarat Campus (Aquinas) is set in the historic gardens of Carn Brea, formerly the property of Cornish miner Cyrus Retallac. The property includes a two-storey mansion, which he built as his family home in 1881. Carn Brea, a castle in Cornwall, was built in the 1500s.
After the Queen's Church of England Girls' Grammar School acquired the property in 1919, the mansion was renamed Manifold House.
Manifold House now accommodates administrative facilities of the campus and staff offices.
The Ballarat Campus had its beginnings in the establishment of the Aquinas Training College by the Ballarat East Sisters of Mercy in 1909. It later became known as Sacred Heart Training College because of its close association with the secondary school of that name in Ballarat East.
In the mid-1960s with increasing enrolments and the demands of a growing school population, the College moved to Patrician House in Victoria Street, Ballarat.
In 1973 the gracious property at 1200 Mair Street, until then the Queen's Church of England Girls' Grammar School, was purchased by the Sisters of St John of God, who conduct the adjacent hospital. In turn, the property was purchased by the Diocese of Ballarat and from 1974 became the new site of the Catholic teachers' college, which was initially known as Aquinas College.
In March 1974, the authorities controlling the Victorian Catholic teachers' colleges relinquished their control to the Institute of Catholic Education. In December 1974, the Institute was admitted as a constituent member of the State College of Victoria.
While initially the Institute was concerned predominantly with the preparation of primary teachers for Catholic schools, by 1980 it had accredited courses concerned with post primary education, nursing, religious education, church music, educational administration, guidance and welfare, educational studies and multicultural studies.
The Institute was federally funded and a fully accredited College of Advanced Education. All courses offered were approved and accredited under the Victorian Post-Secondary Education Act and were nationally registered by the Australian Council of Tertiary Awards.
At the end of 1990 the Institute formally handed responsibility for the Institute and its operations to ACU.