Is It Legal to Carry a Knife in Massachusetts?

Carrying a knife in Massachusetts is legal in most everyday situations, but the state bans several specific knife types outright, restricts knives in certain locations, and can treat any blade as a “dangerous weapon” depending on how you carry or use it. So the honest answer to whether it is legal to carry a knife in Massachusetts is: usually yes for ordinary pocket and utility knives, and no for the categories listed in Massachusetts General Laws Chapter 269, Section 10.

Knife Types That Are Always Illegal to Carry

Section 10(b) prohibits anyone from carrying the following on their person or having them under their control in a vehicle, regardless of why they are carrying them:

Stilettos and daggers
Dirk knives
Double-edged blades (any knife sharpened on both sides)
Ballistic knives (knives with a detachable blade propelled by a mechanism)
Quick-draw sheaths that let a locking-blade knife be drawn in the locked position

The same statute covers other weapons like blackjacks, throwing stars, and nunchucks, but these knife categories are the ones most people run into.¹

A standard folding pocket knife, a kitchen or utility knife, a single-edged fixed blade — none of those are prohibited by type. What makes them legal is both their design and the way you carry them.

Switchblades: The Rules Just Changed

Massachusetts banned switchblades from 1957 until August 2024, when the Supreme Judicial Court ruled in Commonwealth v. Canjura that the ban violated the Second Amendment. The court found that switchblades qualify as “arms” in common use by law-abiding citizens for lawful purposes and struck down the switchblade-specific language in Section 10(b), leaving the rest of the statute intact.²

The legislature responded in 2025 by amending Section 10 to re-regulate switchblades under new conditions rather than banning them outright. The amendment took effect August 5, 2025, and based on available information restricts legal possession to adults 21 and older and limits blade length.¹ Because the rules are new and enforcement practices may still be adjusting, anyone planning to carry a switchblade should check the current statutory text for the exact age and size requirements.

When a Legal Knife Becomes an Illegal Weapon

Even a knife that is legal by type can land you in criminal trouble if the circumstances turn it into a “dangerous weapon.” Massachusetts courts define a dangerous weapon as any object constructed or used in a way likely to cause death or serious bodily harm. That definition can reach objects never designed as weapons — a screwdriver, a baseball bat, even a dog has been held to qualify when used to threaten or attack.

Translated to knives: a pocket knife carried for opening boxes is legal, but the same knife brandished during an argument, or carried with the intent to use it on someone, crosses the line. Police and prosecutors look at the whole picture — where you were, what you were doing, and whether the knife was deployed in a way that suggests you planned to use it as a weapon.

One point of confusion worth clearing up: Massachusetts law does not draw a general distinction between open and concealed carry of knives. Section 10(b) prohibits carrying a banned knife “on his person” or “under his control in a vehicle” without saying anything about whether it is visible. What matters is the type of knife and the circumstances of carry, not where you clip it.

The Firearms License Exception

Section 10 contains a carve-out that surprises many people. Anyone holding a valid License to Carry firearms (an LTC issued under Chapter 140, Section 131 or 131F) “shall not be deemed to be in violation of this section.”³ If you hold an active LTC, you have significantly more latitude in what you can legally carry under the state statute. The exception applies to the weapons listed in Section 10, but it does not override location-specific bans like school zones or federal property.

Where You Can’t Bring a Knife

A handful of locations prohibit knives even when the knife itself is otherwise legal.

Schools and Colleges

Section 10(j) makes it a crime to carry any dangerous weapon, including any qualifying knife, in or on the grounds of an elementary school, secondary school, college, or university. The ban extends to school buses and other student transportation. The only exception is written authorization from the school’s governing board or the officer in charge. The penalty is a fine of up to $1,000 or imprisonment for up to two years, or both.¹

State Government Buildings

Facilities managed by the Division of Capital Asset Management and Maintenance (DCAMM) prohibit knives and edged devices for all visitors and tenants. The DCAMM rule reaches further than Section 10 does: even knives that fall outside the statute are banned inside these buildings. If you arrive with a knife, you have to declare it to security at the entry point. Security may hold the item during your visit, but it will not come inside with you.⁴

Federal Buildings and Post Offices

Federal property has its own rules. Under 18 U.S.C. § 930, carrying a dangerous weapon into a federal facility is a federal crime, but the statute explicitly excludes pocket knives with a blade under 2½ inches.⁵ A small pocket knife is generally fine in most federal buildings; anything larger is not. Federal courthouses frequently enforce stricter screening and bar all knives.

Post offices are governed by 39 C.F.R. § 232.1, which bars any “dangerous or deadly weapons” from postal property, openly or concealed. Unlike the federal building statute, the postal rule contains no explicit exception for small pocket knives.⁶

Airports

The TSA prohibits all knives in carry-on luggage, with the sole exception of rounded, blunt-edged knives without serration. Knives can go in checked bags if they are sheathed or securely wrapped to protect baggage handlers.⁷ Past the security checkpoint, the secured area is effectively a knife-free zone.

Penalties for Carrying an Illegal Knife

The penalties under Section 10(b) escalate sharply with your criminal history:

First offense, no prior felony conviction: a fine of up to $50, or up to two and a half years in a jail or house of correction.
First offense with a prior felony conviction: two and a half to five years in state prison, or six months to two and a half years in a jail or house of correction.
Second offense: five to seven years in state prison.
Third offense: seven to ten years in state prison.
Fourth offense: ten to fifteen years in state prison.

The jump from first to second conviction is the point where this gets serious fast. A first-time offender with a clean record may face only a small fine. A second conviction carries a mandatory minimum of five years in state prison, with no option for a county sentence.¹

Carrying a knife on school grounds is charged separately under Section 10(j), with a maximum fine of $1,000 or up to two years of imprisonment, or both.¹

1
Mass.gov. Mass. General Laws c.269 Section 10
2
Mass.gov. Switchblades – Commonwealth v. Canjura, Supreme Judicial Court, August 27, 2024
3
General Court of Massachusetts. Massachusetts General Laws Part IV, Title I, Chapter 269, Section 10
4
Commonwealth of Massachusetts. Prohibited and Dangerous Items – DCAMM Managed Facilities
5
Office of the Law Revision Counsel. 18 U.S. Code 930 – Possession of Firearms and Dangerous Weapons in Federal Facilities
6
eCFR. 39 CFR 232.1 – Conduct on Postal Property
7
Transportation Security Administration. Sharp Objects