From 1944, Trinity College has cooperated at the advanced degree level with other theological institutions in the Toronto Graduate School of Theological Studies. The success of this enterprise led Trinity to participate in establishing the Toronto School of Theology (TST) in 1969. The resources of nearby theological colleges which were federated or affiliated with the University of Toronto became available to the students and professors of Trinity at both the basic and advanced degree levels. The Toronto School of Theology continues today as a federation of seven colleges representing different Church traditions:
- Emmanuel (United Church of Canada),
- Knox (Presbyterian),
- Regis (Roman Catholic, Jesuit),
- St Augustine's (Roman Catholic, Archdiocese of Toronto),
- St Michael's (Roman Catholic, Basilian),
- Trinity (Anglican and Orthodox), and
- Wycliffe (Anglican, Evangelical).
Six of these colleges are located within walking distance of each other on the main campus of the University of Toronto.
The TST offers a common curriculum and timetable, as well as open access for the students of all colleges to all courses. Thus 1994 marked a half-century of ecumenical higher education in Toronto and a quarter century of the Toronto School of Theology.
In 1978, by a "Memorandum of Understanding", Trinity and the other colleges of the Toronto School of Theology entered into a closer relationship with the University of Toronto for the purposes of higher education in theology. The arrangement brings added resources to the programme, and today means that Trinity and the University of Toronto conjointly award the degrees of M.Div., Th.M., and Th.D., upon approval by the TST.
In addition to the shared resources of the colleges and the university, other centres are available to Trinity students. These include the Ecumenical Forum, the Toronto Institute for Pastoral Education, and the Pontifical Institute of Mediaeval Studies. Many students take their Field Education under ecumenical auspices, either in clinical settings or in urban and social training.
Through the Toronto School of Theology and the University of Toronto, Trinity students and professors enjoy the resources of one of the most important centres of theological education in North America.