Here is a link to the Canadian Government's website showing official and "un-official" tartans.

http://www.canadianheritage.gc.ca/pr...sc-cs/o6_e.cfm

Looks like the official is STA 6627.

My favorite is the Ensign Of Ontario however. That one can be seen here.

http://www.district-tartans.com/ontario.htm

THAT's one I want a kilt from. (STA 2142)

All that being said if you look closely at the tartan maple leaf on the site at the top of this post you'll notice that the picture shown of Ontario tartan is really the Ensign and not the one listed as the "official" tartan.