York University (French: Université York), also known as YorkU or simply YU, is a public research university in Toronto, Ontario, Canada. It is Canada's third-largest university, and it has approximately 53,500 students, 7,000 faculty and staff, and over 375,000 alumni worldwide. It has 11 faculties, including the Lassonde School of Engineering, Schulich School of Business, Osgoode Hall Law School, Glendon College, and 32 research centres.

York University was established in 1959 as a non-denominational institution by the York University Act, which received royal assent in the Legislative Assembly of Ontario on 26 March of that year. Its first class was held in September 1960 in Falconer Hall on the University of Toronto's St. George campus with a total of 76 students. In the fall of 1961, York moved to its first campus at Glendon Hall (now part of Glendon College), which was leased from U of T, and began to emphasize liberal arts and part-time adult education. In 1965, the university opened a second campus, the Keele Campus, in North York, within the neighbourhood community now called York University Heights.

Over the last twenty years, York has become a centre for labour strife with several faculty and other strikes occurring, including the longest university strike in Canadian history in 2018.