I have had a number of people ask what has happened to Newfoundland. It’s not in the 1921 Canada census on Ancestry.ca.
No, it isn’t there because it didn’t become a province until 1949.
However, they did have a 1921 census of Newfoundland and Labrador, and it has been opened for a number of years.
You can access it at the Library and Archives Canada on microfilm , and the transcript is at the Newfoundland Grand Banks website at http://ngb.chebucto.org/C1921/121-dist-idx.shtml
The districts of Bay de Verde, Bonavista, Fogo, and Labrador have not survived.