Massachusetts Knife Law – The Complete Guide (In Plain English)

This article was created to be a brief synopsis of the law according to my understanding and is not legal advice. Knifeade is not a legal service provider. Using this site does not create a client/lawyer relationship. Because knife laws can be interpreted differently by different people and entities it is recommended that you consult legal counsel for specific information and guidance.

If you carry a concealed weapon in Massachusetts, you need to be aware of your legal responsibilities under the state’s knife laws. And whether you rely on your knife for self-defense or hunting, the penalties you face could increase dramatically if you break any of the rules.

Massachusetts knife laws are found in one long-running sentence under section 10-part b. To most people, this law is difficult to understand when they read it for the first (or tenth) time. Below are answers to the most frequently asked questions about MA knife laws.

Does Massachusetts Have Statewide Preemption?

Massachusetts does not have statewide preemption, so different counties within the state can impose stricter knife laws. Therefore, you should always do your due diligence before carrying your knives across counties in Massachusetts to avoid trouble.

Legal Knives in Massachusetts

There is no ban on ownership of any knife in Massachusetts. This means that you can own any of the following knives:

  • Switchblades or automatic knives
  • Balisongs or butterfly knives
  • Throwing or star knives
  • Bowies and other hunting knives
  • Dirks, stilettos, push knives, daggers
  • Ballistic knives
  • Lipstick, cane, and other disguised knives 

However, section 12 of Massachusetts law prohibits manufacturing or selling any instrument or weapon, including knives, switchblades with blades longer than 1.5 inches, klackers, kung fu sticks, and metal knuckles.

What does this mean?

It means that even though you can own any type of knife in the state, you cannot buy it from Massachusetts. Instead, you can order online and have the knives sent to your address or buy from a neighboring state.

Illegal Knives in Massachusetts

There are no restrictions as to which knives you can own in Massachusetts. Note that there is a difference between ownership and carrying knives:

Ownership means you can possess it as long as it is within your home or residential property. The rules significantly change when you walk out of your house carrying a knife in Massachusetts.

Massachusetts Knife Carry Laws

Massachusetts knife carry laws read as follows:

  • Under section 10, it is illegal to carry open or concealed upon a person, including their vehicle, any:
    • Stiletto
    • Dagger
    • Ballistic knives
    • Knives with detachable blades
    • Knives with locking blades that can be drawn at a locked position
    • Dirks
    • Switchblades or automatic knives with blades longer than 1.5 inches
    • Slingshot
    • Metallic knuckles (“brass knuckles”) or anything similar
    • Nunchaku
    • Blowgun
    • Blackjack
    • Throwing knives
    • Double-edged knives
    • Zoobows (Kungfu sticks connected with rope, wire, chain, or leather)
  • It is illegal to carry a loaded or unloaded firearm and any dangerous weapon (which includes prohibited knives listed above) in a courthouse, prison, government building, or school grounds, regardless of the level, without authorization from the board or school officer in charge on the grounds.
  • It is legal to carry pocket knives, multitools, and kitchen knives. However, these can still be viewed as dangerous and illegal weapons by the court if someone intends to harm or if another person fears or feels threatened by a knife that is legal to carry.
  • It is illegal to carry or possess a billy or other dangerous weapon when disturbing the peace or being arrested.

Unfortunately, the 400-word long clause does not provide specific definitions for terms like dangerous weapons or double-edged knives. Therefore, according to the law, it is right to assume that the knives listed under section 10 are the only illegal knives considered dangerous.

However, there are cases where the court borrows its definitions. For example, in the case of Commonwealth vs. Smith, a double-edged knife is defined as a knife whose second blade has a sharp tip. This makes some bowie knives and clip point knives illegal.

Massachusetts Knife Length Laws

The only knife length limit in the state applies to automatic or switchblade knives.

According to the law, any switchblade or automatic knife with a blade longer than 1.5 inches is illegal. Otherwise, you can own and carry any legal knife regardless of blade length.

In Boston, it is illegal to carry upon a person or in your vehicle any knife with a blade longer than 2.5 inches.

The same applies to Salem, Somerville, New Bedford, Lawrence, and Revere, with exceptions to hunters during hunting activities in some counties.

Massachusetts Knife Laws by Demographic

Here’s what the law says about who can carry and own a knife in Massachusetts.

How Old do You Have to be to Carry a Knife in Massachusetts?

Massachusetts has a blanket ban on carrying knives (those listed in section 10,b) and any other dangerous weapons regardless of age.

The only knives legal to carry in Massachusetts are:

  • Pocket knives
  • Multitools or Swiss blades
  • Kitchen knives

Even so, you have to prove that you do not have the intent to harm or behave in a threatening manner to fellow citizens.

How Old do You Have to be to Buy a Knife in Massachusetts?

Section 12 of the Massachusetts law states that it is illegal to manufacture, cause to be manufactured, sell or expose for sale any of the knives listed in section 10,b.

In simple terms, nobody can buy or sell any of the above-listed knives in Massachusetts.

However, this law does not apply across all counties.

For example, in Boston, knife retailers (excluding department and hardware stores) must have a special city license allowing them to sell knives.

Additionally, minors under 18 years cannot buy knives with blades longer than two inches.

Finally, in Cambridge, giving or loaning any person under 18 years a lock-back knife is illegal.

Can a Felon Carry a Knife in Massachusetts?

According to the law, convicted felons are not allowed to carry any knives or dangerous weapons, as mentioned or not in section 10,b. The consequence of this offense is a jail term of five years.

In addition, if you are a first-time offender found guilty of carrying any illegal knives, you will pay a fine of $50 or be imprisoned for two and a half years.

Massachusetts Concealed Carry Knife Laws

You can own any knife you want in Massachusetts, but there is a limit on which knives you can carry and how you can carry them.

Can You Open Carry a Knife in Massachusetts?

According to the law, you cannot open carry any knife listed in section 10,b (dirks, daggers, stilettos, switchblades with 1.5-inch blades, nunchaku, metal knuckles, etc.) It is also illegal to carry any knife or dangerous weapons on school grounds, federal buildings, courthouses, and in your car.

You can carry kitchen knives, multitools, and pocket knives as long as you are not disturbing the peace and without the intention to cause harm or threaten lives.

Can You Conceal Carry a Knife in Massachusetts?

There is no specific law saying you cannot conceal carry a knife. What you should know is that a wide variety of knives, listed under section 10,b that are illegal to carry upon a person or in their vehicle.

Additionally, if you are found with an illegal knife open or concealed carried, disturbing the peace, or during arrest, you will be charged with a crime. Therefore, it is safe to assume that open or concealed carry of knives is illegal in Massachusetts.


At the end of the day, understanding Massachusetts’ knife laws doesn’t seem overly complicated. With that being said, I’m just a normal dude, and working my way through all of the legal jargon was a grind.

So, while I did my best, always check your state website for the most up-to-date information!

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