Trinity College has its origins in Christian Brothers' College, St George's Terrace, Perth founded by Bishop Mathew Gibney and Brother Ambrose Treacy in 1894. From the beginning, both boarders and day students were enrolled, but as the business section of the city expanded, the site became increasingly unsuitable for a boarding school. In 1938, the boarders were transferred to Mount Henry, Manning, to found Aquinas College.
Christian Brothers' College continued as a day school until 1961 when the buildings and land were purchased by the Perth City Council. The College was then transferred to its present location in 1962, and renamed Trinity College.
In 1968 Trinity became a member of the Public Schools’ Association of Western Australia.
Trinity College endeavours to provide a distinctly Catholic environment where the students can form a truly Christian character and where students, parents and teachers can meet in an atmosphere of mutual concern and respect.
Year 11 students moving into Year 12 2024: subject data is due Friday 25 August
Year 7,8,9 students moving into 2024: elective data is due Friday 1 September