The Library and Archives Canada (LAC) offers an online database titled "Canadian Naturalization 1915-1932". It includes over 200,000 individuals who applied for and received status as naturalized Canadians from 1915 to 1932. This database is one of the few Canadian genealogical resources specifically designed to benefit those researchers with roots outside of the British Commonwealth. References located in the database can be used to request copies of the actual naturalization records, which are held by Citizenship and Immigration Canada.
I did a database search with Greece as the country of origin and had 2,699 results. If you have ancestors that migrated to Canada, this may be a great resource for you.
Good luck with your Greek family history research.
Georgia Keilman nee Stryker (Stratigakos)