Knife and Weapons Laws in Canada: What Is Actually Illegal

There is no legal blade-length limit for knives in Canada; what makes a knife illegal is its design (an automatic-opening or disguised knife) or the purpose and manner in which it is carried.

The Blade-Length Myth, Busted

A persistent rumour holds that Canada bans any knife with a blade over some fixed length, most often quoted as 3 inches (about 7.6 cm) or 4 inches (about 10 cm). It is repeated constantly online and even by some retailers. It is not true. The federal Criminal Code contains no measurement-based rule for knife blades at all.

What actually governs whether a knife is legal in Canada comes down to two separate questions: is this specific type of knife a prohibited weapon by design, and, if not, why and how is this person carrying it. A large kitchen knife, a hunting knife, or a folding pocketknife with a long blade is not illegal on its own. A small automatic-opening knife can be illegal regardless of how short its blade is.

Prohibited Weapons: It's About Design, Not Size

Section 84(1) of the Criminal Code defines a "prohibited weapon" as any weapon listed as such in the Regulations Prescribing Certain Firearms and Other Weapons, a schedule maintained federally. For knives, that list targets a small number of specific mechanisms, not blade dimensions:

• Automatic-opening knives (switchblades). Any knife where the blade opens automatically by gravity, centrifugal force, or hand pressure on a button, spring, or other device built into the handle. Many so-called "assisted-opening" knives sold online fall into this category depending on exactly how the mechanism works.
• Butterfly knives (balisongs). Knives with a handle that splits into two hinged parts folding around the blade.
• Push daggers. Knives designed to be gripped in a fist with the blade protruding between the fingers, sometimes called finger-ring knives.
• Belt-buckle knives. Knives disguised as another object, such as a belt buckle, so the blade is concealed within an everyday item.
• Manual centrifugal knives. Knives openable solely by a flick of the wrist using centrifugal force, as distinct from an ordinary folding knife opened by hand.

Possession of any of these is an offence under Criminal Code s 91(2) regardless of why a person has it, where they got it, or whether they intended to use it. Innocent purpose is not a defence to simple possession of a prohibited weapon.

The Two Offences That Catch Ordinary People

Far more knife charges in Canada involve an otherwise completely legal knife than an actual prohibited weapon. Two Criminal Code sections do the work:

Carrying for a purpose dangerous to the public peace (s 88)

Section 88(1) makes it an offence to carry or possess a weapon, including an ordinary knife, "for a purpose dangerous to the public peace or for the purpose of committing an offence." This is what turns a legal pocketknife or kitchen knife into a criminal charge: not the object itself, but the purpose behind carrying it, assessed by the surrounding circumstances, such as where the person was, what they said, and what else was happening at the time.

Carrying a concealed weapon (s 90)

Section 90(1) separately makes it an offence to carry a weapon concealed, unless the person is authorized under the Firearms Act to carry it concealed. This applies whether or not the person had any dangerous purpose at all; concealment alone is the offence.

Both are indictable offences carrying meaningful maximum penalties, and both can be charged even where the knife itself, sold openly at any hardware or kitchen store, is completely legal to own.

Self-Defence Is Generally Not a Lawful Reason to Carry a Knife

This surprises a lot of people. In the United States, "for self-defence" is a common and often-accepted reason to carry a knife or pepper spray. Canadian courts have generally not accepted that reasoning under s 88. Carrying a knife because you are worried about being attacked, without a specific, immediate threat, has repeatedly been treated by Canadian courts as still falling within a "purpose dangerous to the public peace," because the person is prepared to use it against another person if the situation arises. Deciding to carry a weapon "just in case" is not the same as acting in self-defence at the moment force is actually used against you, which is a separate legal question governed by Criminal Code ss 34 and 35. See our guide to self-defence laws in Canada for how the actual defence works once an attack has already started, and why Canada has no "stand your ground" rule.

Pepper Spray, Bear Spray, and Stun Guns

These consumer self-defence products are treated very differently in Canada than in much of the United States:

• Pepper spray or "mace" marketed for use on people meets the definition of a prohibited weapon under the federal regulations (a device designed to injure, immobilize, or incapacitate a person by discharging a noxious substance) and cannot be legally purchased or carried by the general public.
• Bear spray and dog repellent spray are legal to buy and carry for their labelled purpose, deterring an animal. They are registered as pest-control products, not weapons. Carrying bear spray with the actual intent of using it on a person, rather than wildlife, can turn it into a prohibited weapon or support a s 88 charge for the same reason an ordinary knife can.
• Tasers and other stun guns that use electrical current to immobilize a person are prohibited weapons for civilian use in Canada, with narrow exceptions for law enforcement.

A Short Note on Firearms Licensing

Firearms sit under a separate, more heavily regulated regime than knives. Anyone who wants to legally possess a firearm in Canada needs a Possession and Acquisition Licence (PAL), issued after a safety course and background screening, with firearms classified as non-restricted, restricted, or prohibited. Since October 21, 2022, Canada has also frozen the sale, purchase, and transfer of handguns for personal use within the country and blocked bringing newly acquired handguns into Canada, with narrow exemptions for licensed sport shooters and certain professions. This freeze does not affect existing owners' ability to keep and use a handgun they already legally possessed.

Provinces and Municipalities Add Their Own Rules

The Criminal Code sets the national floor, but provinces and cities layer additional restrictions on top of it. It's worth checking local rules before assuming the federal answer is the whole picture:

Always check your specific province's consumer or public-safety legislation and your municipality's bylaws in addition to the federal rules above.

What a Conviction Actually Looks Like

Weapons offences under the Criminal Code are hybrid offences, meaning the Crown can proceed by indictment for more serious circumstances or by summary conviction for less serious ones. Simple possession of a prohibited weapon under s 91 carries a maximum of five years on indictment. Carrying a weapon for a purpose dangerous to the public peace under s 88 carries a maximum of ten years on indictment, reflecting how seriously the courts treat an intent element on top of mere possession. Carrying a weapon concealed under s 90 carries a maximum of five years on indictment. Actual sentences for a first-time offence involving an otherwise-legal knife, with no injury and no aggravating record, are typically far below these maximums, but a conviction still creates a criminal record with all of the consequences that come with one, including travel restrictions and background-check disclosure.

Related Resources

• Canada Criminal Law hub
• Self-Defence Laws in Canada
• Citizen's Arrest in Canada

Disclaimer: This article explains general Canadian federal law on knives and weapons and is not legal advice. Provincial and municipal rules add further restrictions and are not fully covered here. If you are facing a weapons-related charge, consult a criminal defence lawyer licensed in your province.