Wisconsin Knife Laws

At a Glance:

The public carry of knives – openly or concealed and without regard to type or blade length – is not generally restricted in Wisconsin.

Specific restrictions for persons convicted of violent crimes, minors, and sensitive locations apply to knives within the statutory definition of “dangerous weapon,” as discussed in more detail below.

Relevant Statutes:

939.22. Words and phrases defined
(10) “Dangerous weapon” means any firearm, whether loaded or unloaded; any device designed as a weapon and capable of producing death or great bodily harm; any ligature or other instrumentality used on the throat, neck, nose, or mouth of another person to impede, partially or completely, breathing or circulation of blood; any electric weapon, . . . or any other device or instrumentality which, in the manner it is used or intended to be used, is calculated or likely to produce death or great bodily harm.
941.20. Endangering safety by use of dangerous weapon
941.23. Carrying concealed weapon
  (1) (ap) Notwithstanding s. 939.22(10), “dangerous weapon” does not include a knife.
941.231. Carrying a concealed knife
Any person who is prohibited from possessing a firearm under s. 941.29 who goes armed with a concealed knife that is a dangerous weapon is guilty of a Class A misdemeanor.
948.60. Possession of a dangerous weapon by a person under 18
948.61.  Dangerous weapons other than firearms on school premises
66.0409. Local regulation of weapons (preemption)

Restricted Knives:

There are no restricted or prohibited knives.

Concealed Carry:

Concealed carry is not an issue. Knives may be carried openly or concealed.

Restrictions on Sale or Transfer:

It is unlawful under 948.60 to transfer a “dangerous weapon” as defined by 939.22 (10) to a minor. A knife may be considered a dangerous weapon.

Restrictions on Carry in Specific Locations/Circumstances:

Knives are prohibited at all schools K -12, which includes buildings and grounds, athletic fields, recreation areas, and any other property used or operated for school administration. Local governments may restrict the possession of knives at government facilities.

Statewide Preemption:

Yes. Wisconsin law 66.0409, Local regulation of weapons, provides for statewide uniformity. It also contains a provision intended to prevent pretextual”disorderly conduct” violations based on knife possession:

Unless other facts and circumstances that indicate a criminal or malicious intent on the part of the person apply, no person may be in violation of, or be charged with a violation of, an ordinance of a political subdivision relating to disorderly conduct or other inappropriate behavior for . . . or for carrying or going armed with a firearm or a knife, without regard to whether the firearm is loaded or the firearm or knife is concealed or openly carried. Any ordinance in violation of this subsection does not apply and may not be enforced.

Discussion:

§ 941.23 Carrying concealed weapon

Section 941.23 is the general statute applicable to the carry of concealed weapons. Knives are statutorily excluded by sub-part (1) (ap), which provides that for the purpose of this section, “dangerous weapon” does not include a knife.

§ 941.231. Carrying a concealed knife

This section is specific to knives. It provides that persons convicted of a violent crime may not carry a knife concealed if it is a “dangerous weapon” as defined in § 939.22 (10), which, as applies to knives, states:

‘Dangerous weapon’ means. . . any device designed as a weapon and capable of producing death or great bodily harm;  . . . or any other device or instrumentality which, in the manner it is used or intended to be used, is calculated or likely to produce death or great bodily harm. 939.22. (10).

Automatic Knives

Wisconsin enacted a law prohibiting the possession of “any knife having a blade which opens by pressing a button, spring, or other device in the handle or by gravity or by a thrust or movement” in 1959. This statute was applied to a spring-assisted folding knife in a case deriving from in-home possession of the knife by the defendant, who was found guilty and ordered to pay a fine of $100 plus costs. The Wisconsin Court of Appeals held the statute was unconstitutional as applied to the defendant in State v Herrmann 873 N.W.2d 257 on November 24, 2015.

The Wisconsin “switchblade” statute, § 941.24, was repealed on February 6, 2016.

The State v Herrmann decision contains an excellent discussion of constitutional issues pertaining to knives.

Consequences

Violations of Chapter 941 involving knives are Class A misdemeanors and carry a maximum of 9 months confinement and/or a fine of up to $10,000.

Updated January 25, 2023, by Daniel C. Lawson