The Ontario Archives has a database which is an index to the four volumes of assisted immigration registers created by the Toronto Emigrant Office between 1865 and 1883.
The chronological breakdown of the volumes is as follows: -
January 3, 1865 to September 20, 1870
September 26, 1870 to July 31, 1873 and October 2 1874 to Dec. 29, 1876
January 1, 1877 to January 31, 1883
May 24, 1873 to Oct. 2, 18
The first emigrant office in Upper Canada (Ontario) was opened in 1833 in Toronto, headed by AB Hawke.
It is not totally clear which communities other than Toronto, Kingston, and Hamilton had proper "offices" as such, but Hawke received reports from agents in Ottawa, Port Hope, Peterborough, Cobourg, Prescott, and other locations at various times.
Fields such as Date of Application, Nationality, Trade, Destination are filled in when you put a person's name in the database.
The website is http://www.archives.gov.on.ca/english/db/hawke.aspx