https://legalbeagle.com/6659356-knife-laws-canada.html
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Passable Knives
Knives with sheaths, knives that take both hands to open and any knife with a fixed blade are legal in Canada. Knives only become the law's concern in Canada after being used to threaten, injure or kill someone. Due to Canada's strict gun ownership laws, knives killed more people than guns did in Canada between 2000 and 2004.
No Purchase Rules
There are no laws governing the sale of knives in Canada. This may come from Canada's rich hunter/adventurer tradition, but knife vendors are not even required to check a buyer's age before selling a knife. There is also no criminal background check, licensing process or any other examination required to purchase a knife. This is because of how common and useful knives are in everyday life. Sales rules would choke most people's access to a tool with endless peaceful applications.
Possession
Simple possession of a legal knife is not a crime in Canada. However, a prosecutor may be able to argue in court that a small pocket knife was carried for a "purpose dangerous to the public’s peace" or in order to commit a crime. In this case, even possession of a small pocket knife can become a problem. The argument of possession of a knife for self defense has not yet become common law, and cannot be counted on as a blanket defense."
As a deckhand I carry a knife at work, as a citizen I carry a knife everywhere else.