Quick Legal Facts

Statewide Preemption:
Yes, effective February 2016.
Concealed Carry:
Not a problem.
Minors:
Possession of dangerous weapons, or transfer of the same to a minor, is prohibited.
Schools:
Possession of dangerous weapons, other than firearms, on school premises is prohibited.
Critical Dimensions:
None noted.
At a Glance:
Wisconsin law does not generally restrict the possession and carry of knives either openly or concealed. While there is a statute that prohibits the concealed carry of any ‘dangerous weapon’ (941.23), knives are specifically excluded from that prohibition.
The statute captioned ‘Carrying a Concealed Knife’ (941.231) applies to persons convicted of certain crimes, subject to a restraining order, or having a mental disability.
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:
Wisconsin law removes knives from the general concealed carry prohibition but does not similarly bar all knives from being a ‘dangerous weapon’ for purposes of transfers to minors for example. There is essentially no clear appeal court level guidance on what knives, if any, may be dangerous weapons.
The relevant portion of the statutory definition provides:
“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).
Knives clearly designed as a weapon might be considered as dangerous weapons given this definition although very few knives would be included in such a category.
Violations of Chapter 941 involving knives are Class A misdemeanors and carry a maximum 9 months confinement and / or a fine of up to $10,000.
From an overall perspective, Wisconsin allows a very healthy degree of freedom with respect to knives. People in Wisconsin should not become complacent when traveling into neighboring Illinois or other states where more significant restrictions and penalties may apply.
Updated December 10, 2019 by Daniel C. Lawson.