The Archives of Ontario holds civil Vital Statistics registrations including Birth, Marriage and Deaths. Most of these are available on Ancestry.ca except for the later few years that are still held by the Archives.
The Archives of Ontario has the Indexes (where they exist) and Registration Books from the Office of the Registrar General of Ontario for:
Births: 1869-1915 Marriages: [ca. 1801-1930] (Note: There are many gaps in pre-1869 marriage records) Deaths: 1869-1940
All of these records are publicly available on microfilm. Another year of records has been sent to the Archives but these records are restricted until they have been made publicly available. This latest transfer (consisting of the 1916 births, 1931 marriages, and 1941 deaths) is being digitized and will be available some time in 2013. For more recent registrations after these years, you must contact the Office of the Registrar General.
Cemetery transcriptions have been done for a lot of Ontario cemeteries by the various branches of the Ontario Genealogical Society www.ogs.on.ca You would have to know which cemetery you are looking for. The transcriptions are available for purchase from OGS.