He was born to a Burgher family of Dutch-Tamil-Sinhalese-Portuguese origin. He moved to England with his mother in 1954. After relocating to Canada in 1962, Ondaatje became a Canadian citizen. Ondaatje studied for a time at Bishops College School and Bishop's University in Lennoxville, Quebec, but moved to Toronto and received his BA from the University of Toronto and his MA from Queen's University in Kingston, Ontario and began teaching at the University of Western Ontario in London, Ontario. In 1970 he settled in Toronto. From 1971 to 1988 he taught English Literature at York University and Glendon College in Toronto.
He and his wife, novelist and academic Linda Spalding, co-edit Brick, A Literary Journal, with Michael Redhill, Michael Helm, and Esta Spalding.
Although he is best known as a novelist, Ondaatje's work also encompasses memoir, poetry, and film.
Ondaatje has, since the 1960s, also been involved with Toronto's influential Coach House Books, supporting the independent small press by working as a poetry editor.
In 1988 Michael Ondaatje was made an Officer of the Order of Canada (OC) and two years later became a Foreign Honorary Member of the American Academy of Arts and Letters.
He has two children and is the brother of philanthropist, businessman, and author Christopher Ondaatje.
In 1992 he received the Man Booker Prize for his winning novel adapted into an Academy-Award-winning film, The English Patient.