One resource often overlooked when doing genealogy research are University Archives.
Some that I have cited in different posts are The Lost Schools of English Montreal and the Digital Atlas Collections by McGill University and the Mental Healthcare digitization by Glasgow University for the Welcome Trust.
Now a digital project of McGill Universtiy is their War Records, in recognition of the men and women of McGill in wartime service. These records hold not only the index cards on the former students but some files contain newspaper clippings, letters and photos.
The other day I mentioned finding my Dad and uncles' names in the Canada Gazette. There were a couple of mentions but the main one is when the WWII soldiers are "struck off strength" at the end of the war 1946. Type your ancestor's name in the search box on the Canada Gazette Archive page.
I have found a few other sites where you may find mention of your WWII ancestor.
McGill Remembers - War Records
Canada Gazette Archives
Crew Lists from Ships hit by U-Boats
Aboriginal Veterans of WWI, WWII & Korea
WWII at LAC- Service Members who died, Faces of War (photos), etc
Australian War Records Search (by name - and choose category) - click display after
WWII USA Cadet Nurses
The Maple Leaf Scrapbook - WWII
The Navy List (UK)
Related Post: WWII - Before and After D-Day