Colorado generally allows adults to own most common knives, including switchblades and gravity knives, but ballistic knives remain illegal weapons under state law. The main statewide carry risk is concealed carry: Colorado criminalizes carrying a statutory “knife” concealed on the person, and school, college, and university property can create felony exposure for non-firearm deadly weapons. Colo. Rev. Stat. §§ 18-12-102, 18-12-105, 18-12-105.5. (Colorado General Assembly)
Quick Answer
Colorado knife law is more permissive on ownership than on concealed carry and place-based possession. This article provides general legal information, not legal advice, and focuses on the current Colorado statutes reviewed through March 21, 2026, together with recent enacted legislation affecting those statutes. Colo. Rev. Stat. §§ 18-12-101 to 18-12-105.6. (Colorado General Assembly)
The key sections are straightforward. Colo. Rev. Stat. § 18-12-102 defines “illegal weapon” and currently includes ballistic knives, blackjacks, gas guns, and metallic knuckles. Colo. Rev. Stat. § 18-12-105 governs concealed carry of a statutory “knife.” Colo. Rev. Stat. § 18-12-105.5 governs weapons on school, college, and university property, and Colo. Rev. Stat. § 18-12-105.6 gives limited statewide protection for traveling with a weapon in a private vehicle. (Colorado General Assembly)
Colorado does not impose a general statewide ban on ordinary folders, fixed blades, daggers, dirks, stilettos, butterfly knives, switchblades, or gravity knives. The current “illegal weapon” list in Colo. Rev. Stat. § 18-12-102(2) does not include those categories. (Colorado General Assembly)
Ballistic knives are different. Colorado expressly defines a ballistic knife as a knife with a blade forcefully projected from the handle by a spring-loaded device or explosive charge, and possession of an illegal weapon is a class 1 misdemeanor under Colo. Rev. Stat. § 18-12-102(4). Colo. Rev. Stat. §§ 18-12-101(1)(a.3), 18-12-102(2), (4). (Colorado General Assembly)
The current Colorado statutes reviewed do not identify a general statewide ban on openly carrying an ordinary knife. That is the cautious statewide answer. (Colorado General Assembly)
The practical limit is that open carry can still become unlawful in specific places or under local rules. Colorado’s main statewide carry statute for knives targets concealed carry, not open carry, while the school-property statute reaches possession of qualifying non-firearm deadly weapons regardless of concealment. Colo. Rev. Stat. §§ 18-12-105, 18-12-105.5. (Colorado General Assembly)
Concealed carry is the main statewide knife restriction in Colorado. A person commits a class 1 misdemeanor if the person knowingly and unlawfully carries a knife concealed on or about the person. Colo. Rev. Stat. § 18-12-105(1)(a). (Colorado General Assembly)
Colorado’s statutory definition of “knife” matters here. Under Colo. Rev. Stat. § 18-12-101(1)(f), a “knife” means any dagger, dirk, knife, or stiletto with a blade over 3.5 inches, or any other dangerous instrument capable of inflicting cutting, stabbing, or tearing wounds. The same definition says it does not include a hunting or fishing knife carried for sports use, but that point must be raised as an affirmative defense. (Colorado General Assembly)
The statute also contains important exceptions. It is not an offense under § 18-12-105 if the person is in the person’s own dwelling, place of business, or on property under the person’s control, or if the person is in a private automobile or other private conveyance carrying a weapon for lawful protection while traveling. Colo. Rev. Stat. § 18-12-105(2)(a), (b). (Colorado General Assembly)
Automatic knives, switchblades, gravity knives, butterfly knives, and double-edged knives are not broadly banned statewide in Colorado, but ballistic knives remain illegal. That is the clearest current reading of the code. (Colorado General Assembly)
This changed years ago for switchblades and gravity knives. Senate Bill 17-008 removed “gravity knife” and “switchblade knife” from Colorado’s illegal-weapon framework, and the session law states an effective date of August 9, 2017. Colorado’s current source notes also show that repeal. (Colorado General Assembly)
Butterfly knives are not separately listed as illegal weapons in the current statute. Double-edged knives, daggers, dirks, and stilettos are also not categorically banned to own, but daggers, dirks, and stilettos are named in the statutory definition of “knife,” so concealed-carry rules can still apply when the blade is over 3.5 inches or the item qualifies as another dangerous cutting or stabbing instrument. Colo. Rev. Stat. §§ 18-12-101(1)(f), 18-12-105(1)(a). (Colorado General Assembly)
Colorado does not appear to impose a general statewide blade-length cap for ownership or open carry. The 3.5-inch figure is important mainly because it appears in the statutory definition of “knife” used for concealed-carry analysis. Colo. Rev. Stat. § 18-12-101(1)(f). (Colorado General Assembly)
That means the safest summary is narrow: Colorado’s statewide code does not create a universal “all knives over 3.5 inches are illegal” rule. Instead, the 3.5-inch threshold primarily affects whether an item falls within the Article 12 concealed-carry definition. Local rules may separately use similar length cutoffs in particular places. (Colorado General Assembly)
School and campus property create the clearest statewide place restriction for knives in Colorado. Colo. Rev. Stat. § 18-12-105.5 prohibits knowingly and unlawfully possessing a non-firearm deadly weapon on the real estate and improvements of public or private schools, colleges, universities, and seminaries, subject to listed exceptions. (Colorado General Assembly)
That matters because the school statute uses the broader “deadly weapon” definition in Colo. Rev. Stat. § 18-1-901(3)(e), which includes a knife or other weapon capable, in the manner used or intended, of causing death or serious bodily injury. A violation involving a non-firearm deadly weapon is a class 6 felony. Colo. Rev. Stat. §§ 18-1-901(3)(e), 18-12-105.5(1)(a), (1)(b)(I). (Colorado General Assembly)
The statute also contains exceptions and defenses. It is not an offense under § 18-12-105.5 if, among other things, the weapon is unloaded and remains inside a motor vehicle on college or university real estate, the person is in the person’s own dwelling or place of business, the person is traveling in a private vehicle with the weapon for lawful protection, or the weapon is possessed for an approved educational program. Colo. Rev. Stat. § 18-12-105.5(3). (Colorado General Assembly)
Colorado’s 2024 government-building sensitive-space statute is different. Colo. Rev. Stat. § 18-12-105.3 is firearm-specific, so the current code reviewed does not show a general statewide knife ban for all government buildings under that section. (Colorado General Assembly)
The current Colorado statutes reviewed do not identify a general statewide age-based possession ban or retail-sale ban for ordinary knives. That is the cautious statewide answer based on the current code sections reviewed for Colorado weapons law. (Colorado General Assembly)
That said, age does not erase other restrictions. School-property rules still apply, and prohibited-person rules can matter. Colorado’s previous-offender statute covers firearms and “any other weapon that is subject to the provisions of this article 12,” which can affect possession for some people with qualifying felony histories. Colo. Rev. Stat. § 18-12-108(1). (Colorado General Assembly)
Colorado does not appear to have broad statewide knife-law preemption. The code reviewed does not show a sweeping statewide rule that bars cities and counties from regulating knives across the board. (Colorado General Assembly)
Colorado does, however, have a narrower statewide protection for travel with weapons in private vehicles. Colo. Rev. Stat. § 18-12-105.6 says the carrying of weapons in private automobiles or other private conveyances for hunting or lawful protection while traveling is a matter of statewide concern and, subject to the statute’s current wording, local governments may not restrict that ability. The current code notes that the latest amendment to this language took effect January 1, 2025. (Colorado General Assembly)
Yes, local rules can still matter in Colorado. Because broad knife preemption does not appear in the statewide code, city, county, and park rules can still create place-specific restrictions. (Colorado General Assembly)
Denver provides a current official example. Denver Parks and Recreation rules prohibit “weapons” in park facilities and expressly include switchblades and knives with blades greater than 3.5 inches, while also recognizing exceptions such as private-vehicle transport for lawful protection and authorized permitted activities. (Denvergov)
Federal law is separate from Colorado law and still matters in several knife-related situations. Even when Colorado state law allows possession, federal rules can affect interstate commerce, mailing, and possession in federal places. (U.S. Code)
The Federal Switchblade Act, 15 U.S.C. §§ 1241-1245, still regulates switchblade knives in interstate commerce and federal jurisdictions, and it separately addresses ballistic knives. Mailing rules under 18 U.S.C. § 1716 also restrict certain automatically opening, gravity, or inertia-operated knives, and 18 U.S.C. § 930 can apply in federal facilities. (U.S. Code)
For most readers, Colorado is relatively permissive on knife ownership but stricter on concealed carry and school-property possession. The practical risk points are concealed carry of a statutory “knife,” possession of qualifying knives on school or campus property, local place-based rules, and the separate ban on ballistic knives. (Colorado General Assembly)
| Issue | Colorado rule |
|---|---|
| Ownership | Most common knives are legal to own statewide. Ballistic knives remain illegal weapons under Colo. Rev. Stat. §§ 18-12-101(1)(a.3), 18-12-102(2). |
| Open carry | No general statewide open-carry ban for ordinary knives was identified in the current statutes reviewed, but local rules and restricted places can still apply. |
| Concealed carry | Concealed carry of a statutory “knife” is generally prohibited and is a class 1 misdemeanor under Colo. Rev. Stat. § 18-12-105(1)(a). |
| Blade length | Colorado has no general statewide ownership cap by blade length, but 3.5 inches matters because it appears in the concealed-carry definition of “knife” in Colo. Rev. Stat. § 18-12-101(1)(f). |
| Switchblades and gravity knives | Legal under current Colorado state law. SB17-008 removed them from the illegal-weapon definition effective August 9, 2017. |
| Schools and campuses | Possession of a non-firearm deadly weapon on school, college, or university property can be a class 6 felony under Colo. Rev. Stat. § 18-12-105.5, subject to statutory exceptions. |
| Private vehicles | Colorado provides a vehicle-travel protection for carrying a weapon in a private automobile or other private conveyance for hunting or lawful protection while traveling. Colo. Rev. Stat. §§ 18-12-105(2)(b), 18-12-105.6. |
| Local rules | Local ordinances and park rules can still matter because Colorado does not appear to have broad statewide knife preemption. |
Readers who want to compare legal carry rules with maker-built options can explore custom knives.
The main recent Colorado changes affecting knife analysis came in 2017, 2023, 2024, and January 1, 2025. Those are the changes that matter most for a 2026 Colorado knife-law article. (Colorado General Assembly)
In 2017, SB17-008 removed switchblades and gravity knives from Colorado’s illegal-weapon framework, with an effective date of August 9, 2017. In 2023, HB23-1293 updated offense classifications and the current § 18-12-102 text now treats possession of an illegal weapon, including a ballistic knife, as a class 1 misdemeanor effective October 1, 2023. In 2024, SB24-131 took effect July 1, 2024 and expanded the school and campus section to cover non-firearm deadly weapons while also creating a separate firearm-only government-building statute. The current code also notes that § 18-12-105.6 was amended by HB24-1348 effective January 1, 2025. (Colorado General Assembly)
Laws can change, local rules may still apply, and restricted places, intent, and prohibited-person status can all affect whether a knife is lawful in a specific situation. (Colorado General Assembly)
Are switchblades legal in Colorado?
Yes. Colorado removed switchblades from the illegal-weapon definition through SB17-008, effective August 9, 2017, although local place-based restrictions can still matter. (Colorado General Assembly)
Is there a 3.5-inch blade limit in Colorado?
Not as a general statewide ownership ban. The 3.5-inch threshold matters mainly in the Article 12 definition of “knife” used for concealed-carry analysis. Colo. Rev. Stat. § 18-12-101(1)(f). (Colorado General Assembly)
Can a knife be kept in a car in Colorado?
Often yes. Colorado recognizes an exception for carrying a weapon in a private automobile or other private conveyance for lawful protection while traveling, and § 18-12-105.6 limits local restrictions in that context. (Colorado General Assembly)
Are knives allowed on school or college property in Colorado?
Usually not when the knife qualifies as a non-firearm deadly weapon under the statute, unless a listed exception applies. School and campus violations can be serious, including class 6 felony exposure for non-firearm deadly weapons. (Colorado General Assembly)
Are butterfly knives legal in Colorado?
No statewide ownership ban was identified in the current Colorado statutes reviewed. But concealed-carry rules and local rules can still apply depending on the knife and the place. (Colorado General Assembly)
Does Denver have stricter knife rules than Colorado state law?
Yes, in some places. Denver’s current park rules prohibit switchblades and knives with blades greater than 3.5 inches in park facilities, subject to stated exceptions. (Denvergov)
Colorado official sources
Federal official sources