St. Thomas University (also St. Thomas or STU) is a Catholic, English-language liberal arts university located in Fredericton, New Brunswick, Canada. It is a primarily undergraduate university offering bachelor's degrees in the arts (humanities and social sciences), education, and social work to approximately 1,900 students. The average class size is 30 and no class is larger than 60.

The university offers recognized majors in Criminology, Journalism, Human Rights, and Communications and Public Policy. St. Thomas is the home of the Frank McKenna Centre for Communications and Public Policy. The university is unique in Canada for its sole focus on liberal arts and its commitment to social justice.

St. Thomas' notable alumni includes a Canadian prime minister, Brian Mulroney, a New Brunswick premier, Shawn Graham, federal and provincial cabinet ministers, prelates, university presidents as well as several Rhodes Scholars.

St. Thomas University acknowledges the land in which the school is built on as traditional territory of Indigenous communities. These communities include the Wolastoqiyik / Maliseet, and the Mi'Kmaw, and Passamaquoddy / Peskotomuhkati Tribes / Nations, who signed peace treaties with the British Crown in the 1700s.

St. Thomas University traces its institutional origins to the establishment of a Catholic academy in the former community of Chatham, New Brunswick (now Miramichi) in the late nineteenth century. Due to an influx of Irish immigration in northwestern New Brunswick, Chatham saw a need for more centers of education and religious instruction. Officially opened in October 1860, St. Michael's Academy was inaugurated by Bishop James Rogers of the newly formed Diocese of Chatham.

St. Michael's Academy catered to young English-speaking males in the Miramichi River Valley and the growing port town of Chatham. A women's academy was created a year later. St. Michael's consisted of a single wooden structure constructed near the seat of the Diocese of Chatham, the new St. Michael's Cathedral. The institution offered a classical education and was intended to prepare students to study for the diocesan priesthood. From 1865, the school was known as St. Michael's College. It closed for several years in the 1870s and 1880s.

Its uneven operation was curbed by the Basilian Fathers, a religious order who assumed the administration of the College in 1910. Since the Toronto-based religious order already had a Catholic college in the Ontario capital, named St. Michael's College (a federated component of the University of Toronto), St. Michael's in Chatham was renamed St. Thomas College after Thomas Aquinas. It remained a high school and a junior college; however, in 1934, the institution gained degree-granting status from the Government of New Brunswick.

After 1923, the Basilian Fathers transferred the administration of the college to the Diocese of Chatham. The diocese was restructured as the Diocese of Bathurst. Its seat was moved to the primarily francophone community, Bathurst, north of Chatham. While St. Thomas College remained in Chatham, its future remained uncertain. In 1959, the college was subject to territorial changes in the reorganized Diocese of Bathurst. English-speaking parishes and the college were transferred to the Diocese of Saint John with its seat in New Brunswick's major port city. The Bishop of Saint John became the Chancellor of St. Thomas. By mid-century, the economic and social significance of post-secondary institutions saw an increased role of state intervention. In 1960, the institution was renamed St. Thomas University by an act of the New Brunswick Legislature. Under the government of Louis Robichaud, the Royal Commission on Higher Education was launched. Headed by John James Deutsch, a professor and administrator from Queen's University, the commission recommended greater centralization and public funding in post-secondary education.

Arising from the Commission's recommendations, St. Thomas University was encouraged to relocate to the campus of the University of New Brunswick in Fredericton to share facilities. Not without controversy and animosity, St. Thomas University moved to the provincial capital and abandoned its secondary school curriculum. A new campus was built in the Neo-Georgian style by the architects of the University of New Brunswick (Larson & Larson) to complement the campus of its institutional neighbour. It officially welcomed students in October 1964.

St. Thomas University and the University of New Brunswick's Fredericton campus are located in the College Hill neighbourhood in Fredericton. The two institutions share facilities for their student unions, libraries, athletics, and a common heating plant and building maintenance services. Students from STU are permitted to take a certain number of classes at UNB and vice versa. However, STU and UNBF itself are financially and academically separate. STU is able to offer many amenities other smaller schools cannot, in large part to its UNB partnership. The two universities enjoy a good-natured rivalry.

STU offers the following programs: Bachelor of Arts, Bachelor of Applied Arts, Bachelor of Education, Bachelor of Social Work, and a Bachelor of Arts Aviation Stream.

STU offers athletic programs for men's and women's basketball, cross-country, soccer, and volleyball, as well as women's rugby and hockey. Collectively, the Tommies have won 41 ACAA titles and 3 AUS titles. Student-athletes have achieved 404 CCAA National Scholar and 417 U Sports Academic All-Canadian awards.

STU participated in AUS men's hockey until 2016 (winning the championships in 1961 and 2001), and men's and women's track and field from 2011-2022.

There are six academic buildings on campus housing classrooms and faculty offices: James Dunn Hall, Edmund Casey Hall, George Martin Hall, Brian Mulroney Hall, Holy Cross House, and Margaret Norrie McCain Hall. Additionally, there are three residence buildings at St. Thomas University, all located on campus: Harrington Hall, Vanier Hall, and Holy Cross House.

The university maintains its own campus police force, comprised by students hired annually by the University to maintain security at campus events. The student newspaper, The Aquinian, is available on campus and throughout the city during the regular academic year.

Bishop of Chatham (1910–1938) after Bishop of Bathurst (1938–1959)

• Thomas Francis Barry, 1910–1920
• Patrice Alexandre Chiasson, C.I.M., 1920–1942
• Camille-André LeBlanc, 1942–1959

Bishop of Saint John (1959–2019)

• A.B. Leverman, 1959–1968
• Joseph Neil MacNeil, 1969–1973
• Arthur Gilbert, 1974–1986
• J. Edward Troy, 1986–1997
• J. Faber MacDonald, C.S.C, 1998–2006
• Martin William Currie, (acting chancellor), 2006–2007
• Robert Harris, 2007–2019

lay Chancellors (2020–Present)

• Graydon Nicholas, since 2020

• Nicholas Roche, C.S.B., 1910–1911
• William J. Roach, C.S.B., 1911–1919
• Frederick Meader, C.S.B., 1920–1923
• Raymond Hawkes, 1923–1927
• James M. Hill, D.D., 1928–1945
• Charles V. O'Hanley, 1945–1948
• A.L. McFadden, 1948–1961
• Donald C. Duffie, 1961–1975
• George W. Martin, 1975–1990
• Daniel W. O'Brien, 1990–2006
• Michael W. Higgins, 2006–2009
• Dennis Cochrane, C.M., 2010–2011
• Dawn Russell, LL.M., 2011–2022
• Kim Fenwick, Ph.D. (Acting), 2022—2023
• M. Nauman Farooqi, Ph.D., 2023—Present

• 
  Shawn Graham, former Premier of New Brunswick
• 
  Brian Mulroney, former Prime Minister of Canada
• 
  Candy Palmater, Miꞌkmaq comedian & activist
• 
  David Adams Richards, Senator & author
• 
  Greg Thompson, Minister of Veterans Affairs

• T.J. Burke - first Indigenous person elected to a legislative assembly in Atlantic Canada and former Attorney General of New Brunswick
• Mike Eagles – former NHL hockey player
• Noël Kinsella – former Speaker of the Senate of Canada
• Kelly Lamrock – former provincial cabinet minister and Attorney General of New Brunswick
• Graydon Nicholas – first Indigenous Lieutenant Governor of New Brunswick, former judge, and first Indigenous law graduate from Atlantic Canada
• David Adams Richards – former writer-in-residence
• Jan Wong – journalist and author

• Higher education in New Brunswick
• List of universities in New Brunswick
• Atlantic University Sport
• Canadian Interuniversity Sport
• The Thomists (21-piece big band based at the university)

• Fraser, J. A. "By Force of Circumstance": A History of St. Thomas University. Fredericton: Miramichi Press, 1970.
• Spray, William and Anthony Rhinelander. Church, Politics, and STU: The Relocation of St. Thomas University from Chatham to Fredericton. Fredericton, NB: STU, 2014.

• Official website
• STU Tommies Athletics

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