The Archives of Ontario (Archives publiques de l'Ontario in French) is the provincial archives for the province of Ontario, Canada. Founded in 1903, the archives is located in Toronto.
The Bureau of Archives, as it was originally known, was first located at the Ontario Legislature. The Archives moved to the Canadiana Building on the University of Toronto campus in 1951, at which time it was known as the Department of Archives. Relocated to 77 Grenville Street in 1972 its name was also changed to the Archives of Ontario. The reading room at the Grenville building closed on March 26, 2009.
The official groundbreaking ceremony for the new Archives of Ontario building on the York University grounds, which also houses the York University Research Tower, was on April 30, 2007. The groundbreaking was attended by former Minister of Government Services Gerry Phillips and former York University President and Vice-Chancellor Lorna Marsden. The building was opened to the public on April 2, 2009 and is expected to be the site of the Archives for at least the next thirty-five years.