Colorado Knife Laws

Italian Stiletto

Colorado Knife Laws

The laws regarding the possession of knives and edged weapons in Colorado may be found at Title 18, and in particular, Article 12 (Offenses Relating to Firearms and Weapons).


Effective August 9, 2017, the restrictions on automatic or gravity knives has been removed from the definition of illegal weapons § 18-12-102.   Still illegal as a dangerous weapon is a ballistic knife definied in § 18-12-101 as:

Ballistic knife means any knife that has a blade which is forcefully projected from the handle by means of a spring-loaded device or explosive charge..


Carrying a concealed knife in Colorado with a blade in excess of three-and-one-half inches (3½) in length is a violation of law. The Colorado concealed weapon statute provides that it is a crime to carry a knife concealed on or about the person.§ 18-12-105(1)(a). Knife is statutorily defined as follows:

Knife means any dagger, dirk, knife, or stiletto with a blade over three and one-half inches in length, or any other dangerous instrument capable of inflicting cutting, stabbing, or tearing wounds, but does not include a hunting or fishing knife carried for sports use. The issue that a knife is a hunting or fishing knife must be raised as an affirmative defense.

Affirmative defense means that the burden on the knife owner to prove that he or she was carrying a knife for sports use and that the knife qualifies as a hunting or fishing knife.

It is legal to carry a knife with a blade length of less than three-and-one-half (3-1/2) inches either openly or concealed. The Colorado Supreme Court has interpreted the unlawful carrying statute as prohibiting the conviction of a person for carrying a knife with a blade less than three-and-one-half inches (3½) in length, absent proof that the person intended to use the knife as a weapon. Moreover, such intent cannot be inferred solely from the appearance of the knife in question. A.P.E., a Juvenile v. The PEOPLE of the State of Colorado, 20 P.3d 1179 (Colorado Supreme Court 2001).

Critical Dimensions:

Three-and-a-half inches“any blade length longer than three-and-a-half inches is a knife, which cannot legally be carried concealed, with specific exceptions for hunting, fishing or sport use.

Statewide Preemption:

Section 18-12-105.6 offers limited protection to knife owners by providing that state law prevails when someone is traveling in a private vehicle or other private means of transportation.  However, if you are not traveling in a private vehicle, local laws may apply.


Deadly weapons may not be possessed on school grounds. This applies to all educational levels, elementary through university (K through post-graduate)§ 18-12-105.5 For purposes of this section, the definition of deadly weapon includes a knife (a defined term as set forth above).  There are several exceptions, including a knife stored inside a vehicle.

This information is presented as a brief synopsis of the law and not as legal advice.

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