The 1851 Canadian Census is now online.
Please note the area covered in this census isn't what we term Canada today.
http://www.collectionscanada.ca/archivi ... dex-e.html
It's not name searchable.
So unless you've an awfy lot of spare time, you need to have a fair idea of where a person might be.
It's very useful for any of us with rellies in those areas; and free too.
Jack