Loss of Canadian citizenship
Under current law there is no provision for involuntary loss of Canadian citizenship except:
naturalized Canadians can be deprived of citizenship if convicted of fraud in relation to their citizenship application, or their original admission to Canada as an immigrant
second-generation Canadians by descent may lose Canadian citizenship automatically on their 28th birthday if they do not meet the requirements for retention
Many Canadians lost Canadian citizenship prior to 15 February 1977 through:
naturalization in another country
long residence overseas (prior to 1967)
if a child, based on a parent’s loss of Canadian citizenship
See History of Canadian citizenship
A Canadian citizen who holds another nationality may in some cases renounce Canadian citizenship voluntarily.