The present St Patrick's College is blessed with a threefold tradition that began on February 2nd, 1872 when the Presentation Sisters taught pupils at their convent in Launceston. With its small beginning, Sacred Heart College was established. The growing need for the education of Catholic children in Launceston was further met by the arrival of the Christian Brothers and the opening of St Patrick's College at York Street on February 3rd, 1919. The third branch of the threefold educational tradition in Launceston began with the establishment of the St Thomas More's School under the auspices of the Sisters of St Joseph in March, 1938.

The three schools flourished and the Religious Orders made a significant contribution to the Catholic community of Launceston at a time when prejudice and lack of financial assistance from the Government made the education of young Catholic children an important priority but also a difficult enterprise.

Despite the hardships of earlier years, the Catholic community of Launceston continued to invest in the education of their children. On February 5th, 1958, the Christian Brothers opened a new campus for St Patrick's College at Prospect Vale. This became a secondary College for boys.

Further financial strain and the challenges of a more extensive curriculum soon led to an amalgamation of the two secondary girl's Colleges of Sacred Heart and St Thomas More's. On the 3rd of March, 1978, the two schools joined to form Marian College.

Finally, in order to provide a continued high standard of education for the Catholic families of Launceston, a further amalgamation of schools occurred when St Patrick's College and Marian College joined to create the new coeducational secondary College which is St Patrick's today. This major shift in Catholic education took place at the beginning of 1984.

In 1998, the Year 7 classes left the Newstead campus and came to join the other classes at Prospect. The process of amalgamation to a Catholic College on a single campus was soon complete.