Montana Knife Laws

montanaMontana knife laws are vague and lack definitions and specifics that can make it difficult to determine exactly what is legal and what is not. This article will show you what specific sections of the law say, and explain, in plain English, what it all means.

What the Law States

45-8-316  Carrying concealed weapons.

(1)  A person who carries or bears concealed upon the individual’s person a dirk, dagger, pistol, revolver, slingshot, sword cane, billy, knuckles made of any metal or hard substance, knife having a blade 4 inches long or longer, razor, not including a safety razor, or other deadly weapon shall be punished by a fine not exceeding $ 500 or by imprisonment in the county jail for a period not exceeding 6 months, or both.

(2)  A person who has previously been convicted of an offense, committed on a different occasion than the offense under this section, in this state or any other jurisdiction for which a sentence to a term of imprisonment in excess of 1 year could have been imposed and who carries or bears concealed upon the individual’s person any of the weapons described in subsection (1) shall be punished by a fine not exceeding $ 1,000 or be imprisoned in the state prison for a period not exceeding 5 years, or both.

That law is clear about what knives you may not carry concealed, and allows for an enhanced sentence for those who are convicted of carrying a concealed weapon for the second time, with the maximum jail time going from 6 months for a first offense to 5 years for second and subsequent offenses.

What is Legal to Own

It is legal to own a dirk, dagger, stiletto, or other push knife
It is legal to own a Balisong, or butterfly knife
It is legal to own a Bowie knife, or other large knife
It is legal to own throwing knives or throwing stars
It is legal to own disguised knives such as cane knives and lipstick knives

What is Illegal to Own

A switchblade knife is illegal to own in Montana unless you are a collector who is registered with the Sheriff in the county where your collection is kept.

Limits on Carry

It is illegal to conceal carry a dirk
It is illegal to conceal carry a dagger
It is illegal to conceal carry any knife with a blade four inches long, or longer
It is illegal to possess or carry any knife with a four inch blade or longer in a school building
It is illegal to conceal carry any weapon while intoxicated
It is illegal to conceal carry a weapon into a government office, bank or financial institution, or a place that sells alcohol for onsite consumption
It is illegal to conceal carry any “deadly weapon”
It is legal to open carry any knife that is legal to own in Montana
It is legal to carry any knife that is legal to own in your vehicle, concealed or openly

Definitions of Various Knives

A switchblade knife is defined by Montana statute as any knife that with a blade that is 1 ½ inches long or longer and that opens automatically by pressing a button or other device on the handle of the knife.

Montana statue and case law fail to define any other type of knife, although various kinds of knives are mentioned in different criminal cases, none are described or defined. When statutes are silent on the definition of a word, and the Courts have not offered a definition, the Courts generally look for the words plain and ordinary meaning, oftentimes turning to Webster’s Dictionary for help. However, until a word has been defined by the legislature or the Court, you really cannot know how the state will define it, making it difficult to be certain whether a particular knife is legal to conceal carry or not.

Definition of Deadly Weapon

Montana code § 45-2-101 defines “weapon” any instrument that is readily capable of being used to produce death or serious bodily injury, regardless of its primary function.

Definition of Concealed Carry

Montana code § 45-8-315 defines concealed weapon, in terms of knives, as carrying any dirk, dagger, or knife with a blade four inch longer or longer, so that it is completely or partially covered by the carriers clothing. Note, that the law does not define concealed weapon as one which is concealed inside a vehicle, and this type of concealed carry is legal is Montana.

Exceptions to the Concealed Carry Law

The law in Montana exempts several classes of people from the concealed carry law, and allows concealed carry of weapons for certain government employees and members of the National Guard. The law also exempts those who are outside the boundaries of a city or town and are participating in lawful recreational activities where it is common to carry a weapon, such as hunting, fishing, trapping, framing, ranching, or hiking. A person is also exempt from the concealed carry law when he or she is carrying the weapon in his or her own home or place of business, or has a permit to carry a concealed weapon.

Concealed Weapon Permits

The laws covering Montana concealed weapon permits do not restrict the carried weapon to a fire arm, allowing for the concealed carry of knives which would otherwise be illegal to conceal carry. In order to obtain a concealed carry permit, one must be at least eighteen years of age, possess a valid Montana driver’s license or other photo identification issued by the state, and have been a resident of Montana for at least six months. Applications for a conceal carry permit may be denied if the applicant has been convicted of a felony or any sex crime, whether a felony or not, was dishonorably discharged from any branch of the service, or has been found by a Court of law to be mentally ill or an abuse of an illegal substance. All applicants must complete some type of firearm educational course, unless he or she served in the military and was found to be qualified to handle and operate firearms.

Conclusion on Montana Knife Laws

Montana allows residents to posses and open carry any type of knife, except for switchblade knifes.

Dirks, daggers, knives with blades 4 inches or longer, and any instrument that may be considered a deadly weapon cannot be conceal carried, unless the carrier has a conceal carry permit or is outside of the city limits and engaged in an activity where it is common to carry a weapon.

Statutes and case law in Montana fail to define any type of knife besides a switchblade knife, so it may be difficult to tell if a specific knife may be conceal carried, and it is probably best to simply always open carry in Montana.


Mont. Code Anno., § 45-8-361 (2012)
Mont. Code Anno., § 45-8-315 (2012)
Mont. Code Anno., § 45-8-316 (2012)
Mont. Code Anno., § 45-8-317 (2012)
Mont. Code Anno., § 45-8-328 (2012)
Mont. Code Anno., § 45-8-331 (2012)
Mont. Code Anno., § 45-2-101 (2012)
Mont. Code Anno., § 45-8-321 (2012)


  1. does a sheath count a clothing? say I’m wearing a knife on my belt that’s over four inches, you can see the bottom of the sheath coming from under my sweatshirt but u can’t actually see the knife. btw I’m 13 turning 14 in two weeks so I am a minor

    1. yes, a sheath is a concealer. if you want to carry it around public you will need a permit. But since your blade length is over 4in it doesn’t change the fact that it’s already illegal to carry to begin with. Spring-assisted knives, however, can be legal to carry because it is NOT a fixed blade and DOES NOT require a push of a button. If your planning to carry a knife around public, I’d say get a spring-assisted one, Karambit is my favorite to carry. Btw, if you’re seen pulling out any type of knife looking thing in public, you can get one hell of a problem, so don’t think itll be cool to show off your friends in public that ur carrying a weapon. (you’ll think it’s cool, but you’ll know it isnt in several year. aka, GL getting a good or any kind of job).

  2. 45-8-317. Exceptions. (1) Section 45-8-316 does not apply to:
    (a) any peace officer of the state of Montana or of another state who has the power to make arrests;
    (b) any officer of the United States government authorized to carry a concealed weapon;
    (c) a person in actual service as a member of the national guard;
    (d) a person summoned to the aid of any of the persons named in subsections (1)(a) through (1)(c);
    (e) a civil officer or the officer’s deputy engaged in the discharge of official business;
    (f) a probation and parole officer authorized to carry a firearm under 46-23-1002;
    (g) a person issued a permit under 45-8-321 or a person with a permit recognized under 45-8-329;
    (h) an agent of the department of justice or a criminal investigator in a county attorney’s office;
    (i) a person who is outside the official boundaries of a city or town or the confines of a logging, lumbering, mining, or railroad camp or who is lawfully engaged in hunting, fishing, trapping, camping, hiking, backpacking, farming, ranching, or other outdoor activity in which weapons are often carried for recreation or protection;
    (j) the carrying of arms on one’s own premises or at one’s home or place of business; or
    (k) the carrying of a concealed weapon in the state capitol by a legislative security officer who has been issued a permit under 45-8-321 or with a permit recognized under 45-8-329.
    (2) With regard to a person issued a permit under 45-8-321, the provisions of 45-8-328 do not apply to this section.

    1. As long as it is EASILY able to be noticed by the public (which shouldn’t be hard with a sword) you could walk around with a greatsword if you wanted. Have fun.

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