Higher education in Ontario includes postsecondary education and skills training regulated by the Ministry of Colleges and Universities and provided by universities, colleges of applied arts and technology, and private career colleges. The current minister is Jill Dunlop who was appointed in June 2021. The ministry administers laws covering 22 public universities, 24 public colleges (21 Colleges of Applied Arts and Technology (CAATs) and three Institutes of Technology and Advanced Learning (ITALs)), 17 privately funded religious universities, and over 500 private career colleges. 18 of the top 50 research universities in Canada are in Ontario.

The Constitution of Canada provides each province with the responsibility for higher education; there is no corresponding federal ministry of higher education. Within Canadian federalism the division of responsibilities and taxing powers between the Ontario and Canadian governments creates the need for cooperation to fund and deliver higher education to students. Each higher education system aims to improve participation, access, and mobility for students. There are two central organizations that assist with the process of applying to Ontario universities and colleges: the Ontario Universities' Application Centre and Ontario College Application Service. While application services are centralized, admission and selection processes vary and are the purview of each institution independently. Admission to many Ontario postsecondary institutions can be highly competitive. Post-secondary students in Ontario are typically represented by student unions affiliated with one of several provincial or national student associations.

The Constitutional Act of 1791 by the British House of Commons divided the old province of Quebec into two British colonies. The western colony became Upper Canada with John Graves Simcoe as its first head of state by fulfilling the role of Lieutenant Governor. Governor Simcoe was the first advocate for establishing educational institutions in the new colony to increase citizens' connection to Britain and prevent the incursion of influence from post-revolutionary schools in the United States. In 1797, the Duke of Portland agreed, on behalf of the British King, to the request from the Legislative Council and House of Assembly of Upper Canada for a portion of Crown Land to support the foundation of grammar schools and a college or university. Higher education preceded Canadian Confederation with the establishment of private and sectarian universities in Ontario during the early 19th century. Initially, Ontario's first three universities were formed with religious affiliations.

Established in 1827, King's College was associated with the Church of England through its first president John Strachan, which was later secularized by the government of Upper Canada to become the University of Toronto. The Presbyterian Church established Queen's College in 1841. In addition, the Roman Catholic Missionary Oblates of Mary Immaculate established the College of Bytown in 1848. In 1866, the College of Bytown completed its conversion to the University of Ottawa through incorporation by Royal charter from the government in London, England. In 1912, Queen's College ended its affiliation with the Presbyterian Church and became Queen's University.

In 1867, section 91 of the Canadian constitution established that the government of Canada has responsibility for trade and commerce whereas section 93 conferred to each province responsibility for education. Higher education in Canada reflects this division of powers in Canadian federalism through the overlapping of interests and responsibilities between the provinces and the federal presence in higher education in Canada. In 1868, the province of Ontario withdrew financial support for religious universities. In 1874, the Canadian government established the first federal institution of higher education in Kingston, Ontario, the Royal Military College of Canada.

In 1876, the Ontario Society of Artists founded the forerunner to the Ontario College of Art & Design at the Toronto Normal School. In 1878, Bishop Isaac Hellmuth founded the "Western University of London" with religious affiliation to the Anglican Diocese of Huron and later the institution became the non-denominational University of Western Ontario. In 1887, William McMaster founded McMaster University by merging Toronto Baptist College and Woodstock College. By 1899, there were seven higher education institutions established in Ontario.

In 1900, the Dominican Order established the Dominican College of Philosophy and Theology that later became the Dominican University College. In 1906, controversy over the role of the Ontario government and the leadership of the University of Toronto led to the Flavelle commission that articulated a separation of powers, resulting in the widespread adoption of the bicameral model for university governance in Canada. In 1911, the Evangelical Lutheran Church in Canada founded the Waterloo Lutheran Seminary that was associated with the development of the University of Waterloo and Wilfrid Laurier University.

Higher education was a low-priority under the provincial government of Mitchell Hepburn due to the effects of the Depression but universities supported the national war effort through funding from the government of Canada. In 1942, the Ottawa Association for the Advancement of Learning established the non-denominational Carleton College that later became Carleton University. By 1945, there were three publicly supported secular universities, six denominational private colleges, and several vocational institutes.