Massachusetts Knife Laws in 2025: What You Can and Can’t Carry
A practical guide to automatic knives, banned blade types, local ordinances, restricted locations, and penalties.
Disclaimer: This article is for general informational purposes only and is not legal advice. Knife laws can change, and local rules may vary, so consult a qualified Massachusetts attorney or the relevant local authority before relying on this information.
Quick answer: Massachusetts knife laws changed after the 2024 Canjura decision, but they are still easy to misread. Adults may carry certain automatic knives if they meet strict age and blade-length rules, while several knife types and many locations remain off-limits.
If you carry a pocket knife, switchblade, or everyday-carry blade in Massachusetts, state law is only the starting point. City ordinances, school-zone rules, and restricted locations can all change what is legal the moment you cross a city line or walk onto certain property.
Massachusetts Knife Laws at a Glance
Adults 21 and older can carry automatic knives with blades under 3 inches, including switchblades and out-the-front knives
Stilettos, daggers, dirks, double-edged knives, and ballistic knives remain banned statewide
Boston, Cambridge, Worcester, and Malden each have their own local ordinances with stricter limits
All knives are prohibited in schools, within 300 feet of school grounds, government buildings, courthouses, and airports
First offense for carrying a prohibited knife can result in 2.5 to 5 years in state prison
Concealed carry of any knife that could be classified as a dangerous weapon remains risky
What Changed After the 2024 Canjura Decision?
In 2024, the Massachusetts Supreme Judicial Court struck down the state’s long-standing ban on automatic knives. That ban had made switchblades illegal to carry in public since 1957.
The decision in Canjura followed the U.S. Supreme Court’s 2022 New York State Rifle & Pistol Association v. Bruen ruling, which changed how courts review weapon restrictions under the Second Amendment.
Justice Serge Georges Jr. wrote that nothing about switchblades makes them uniquely dangerous compared with other knives. The court’s ruling ended the blanket ban on automatic knives, but it did not make every knife legal to carry in Massachusetts.
The Current Rules Under 2025 Legislation
After Canjura, Massachusetts lawmakers passed new 2025 knife legislation. The new rules allow ownership and public carry of automatic knives only when the carrier and knife meet specific requirements.
Knife Type | Legal Status | Conditions |
Switchblades | Legal | Blade under 3 inches, carrier must be 21+ |
Out-the-front knives | Legal | Blade under 3 inches, carrier must be 21+ |
Spring-assisted knives | Legal | Blade under 3 inches, carrier must be 21+ |
Stilettos | Illegal | Banned statewide |
Daggers | Illegal | Banned statewide |
Dirks | Illegal | Banned statewide |
Double-edged knives | Illegal | Banned statewide |
Ballistic knives | Illegal | Banned statewide |
The 3-inch blade limit and 21-and-older requirement are key. If either rule is not met, carrying an automatic knife can still lead to criminal charges.
Knives That Are Still Banned in Massachusetts
Canjura did not legalize every knife. Massachusetts still bans stilettos, daggers, dirks, double-edged knives, and ballistic knives statewide, regardless of blade length or intended use.
The law also covers knives designed mainly for offensive use. That wording gives prosecutors room to charge cases involving knives that do not fit neatly into a named banned category but appear intended as weapons.
Why the “Dangerous Weapon” Classification Matters
Massachusetts law treats certain knives as dangerous weapons, creating criminal liability when they are possessed in specific contexts. Knives fall into this category in several ways. The knives listed above as prohibited are automatically considered dangerous weapons.
Any other knife designed for bodily assault or defense also qualifies. Beyond that, any knife used dangerously can be classified as a dangerous weapon at the time of an arrest or during the commission of a crime.
This classification matters because concealed carry of any knife that could be deemed a dangerous weapon is generally illegal. Carrying a fixed blade under your jacket, for example, creates legal exposure even if the knife itself is otherwise legal to own.
Local Knife Laws Can Be Stricter Than State Law
Massachusetts does not have statewide preemption for knife laws. That means cities and towns can create stricter local knife rules, so a knife that is legal under state law may still be illegal in Boston, Cambridge, Worcester, Malden, or another municipality.
Boston
Boston limits blade length to 2.5 inches. Individuals under 18 may not purchase a knife with a blade longer than 2 inches. These restrictions apply throughout the city limits.
Cambridge
Cambridge law prohibits giving or lending a lock-back knife to anyone under 18. Adults can carry lock-back knives, but transferring one to a minor creates criminal liability.
Worcester
Worcester applies a 2.5-inch limit if you are found with a knife while being arrested for another crime. The restriction ties blade length to contact with law enforcement rather than general carry.
Malden
Malden prohibits any knife with a blade over 2.5 inches. This limit applies broadly, making it one of the state’s stricter municipal ordinances.
For everyday carry, treat the strictest rule in your regular travel area as your real limit. In many Massachusetts cities, that means staying at or below a 2.5-inch blade.
Places Where Knives Are Off-Limits
Some places are off-limits no matter what kind of knife you carry. Massachusetts law prohibits dangerous weapons in schools and educational institutions, including elementary schools, secondary schools, colleges, universities, school buildings, school grounds, and the 300-foot area around school property.
Even a lawful knife can become a problem in these areas unless you have written authorization from the board or officer in charge. The rule applies broadly to parents, visitors, employees, and students.
Knives are also restricted in government buildings, courthouses, airports, and transportation hubs. Expect security screening at these locations to flag knives, which can lead to confiscation or criminal charges.
Penalties for Knife Law Violations
Massachusetts penalties for illegal knife carry can be serious. Depending on the knife, location, and prior record, a violation can mean fines, jail time, or state prison.
First Offense
A first offense for carrying a prohibited knife is punishable by imprisonment of not less than 2.5 years and not more than five years in state prison. Alternatively, the sentence can range from 6 months to 2.5 years in jail or in a house of correction.
If the court finds the defendant has no prior felony conviction, the penalty may be reduced to a fine of not more than $50 or imprisonment of not more than 2.5 years in a jail or house of correction.
Second Offense
A second or similar offense carries a minimum of five years and a maximum of seven years in prison.
School Zone Violations
Violations on school grounds are punishable by a fine of up to $1,000, imprisonment for up to one year, or both.
Practical Tips for Everyday Carry
For everyday carry in Massachusetts, the safest approach is simple: keep the blade under 2.5 inches, choose a single-edged folding knife, and avoid designs that look primarily offensive. Also check the local rules in every city where you work, travel, or spend time.
Automatic knives may now be legal for adults 21 and older if the blade is under 3 inches. But Boston, Worcester, and Malden have stricter 2.5-inch local limits, so a knife can be legal statewide and still violate a city ordinance.
Concealed carry is still risky. If the knife is carried in a way that suggests offensive intent, officers or prosecutors may treat it as a dangerous weapon even if it is otherwise legal to own.
Bottom Line: Know the Rule Before You Carry
Massachusetts knife law is more flexible than it was before 2024, but it is still restrictive. Canjura opened the door for automatic knives, and the 2025 law added age and blade-length limits.
At the same time, banned knife categories remain in place, local ordinances create a patchwork of rules, and schools, courthouses, airports, and government buildings remain high-risk areas for knife carrying.
Before carrying a knife in Massachusetts, check three things: state law, local city ordinances, and the places you plan to go. A knife that is legal on one sidewalk may be illegal near a school or inside a courthouse. Because penalties can range from fines to prison time, knowing the rules is essential.
Source: Yong-Soo Chung, URBANEDC.COM
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