Are Automatic Knives Legal in Missouri?
The Short Answer
Yes. Automatic knives — including switchblades and OTF knives — are legal to own and carry in Missouri. The state removed switchblades from its prohibited weapons list in 2012, and further amended its concealed carry laws in 2017 to narrow the places where concealed weapons are restricted.
Missouri is one of the most permissive states in the country for knife owners. You can own any type of knife. You can open carry any knife. And for concealed carry, the restrictions are limited to specific locations rather than blanket prohibitions on knife types.
There's one nuance to understand: Missouri law still distinguishes between "ordinary pocketknives" (4-inch blade or less) and "knives" (everything else). That distinction matters for concealed carry into firearms-restricted areas. But for day-to-day ownership and carry, Missouri treats automatic knives like any other legal knife.
What Missouri Law Actually Says
The Key Statutes
§ 571.010 — Definitions:
"(12) 'Knife', any dagger, dirk, stiletto, or bladed hand instrument that is readily capable of inflicting serious physical injury or death by cutting or stabbing a person. For purposes of this chapter, knife does not include any ordinary pocketknife with no blade more than four inches in length."
"(21) 'Switchblade knife', any knife which has a blade that folds or closes into the handle or sheath, and: (a) That opens automatically by pressure applied to a button or other device located on the handle; or (b) That opens or releases from the handle or sheath by the force of gravity or by the application of centrifugal force."
§ 571.030 — Unlawful Use of Weapons:
"A person commits the offense of unlawful use of weapons, except as otherwise provided by sections 571.101 to 571.121, if he or she knowingly: (1) Carries concealed upon or about his or her person a knife, a firearm, a blackjack or any other weapon readily capable of lethal use into any area where firearms are restricted under section 571.107."
What That Means in Plain English
Missouri's knife law works in layers:
Ownership: All knives are legal to own. No type restrictions. Switchblades, OTFs, automatics, gravity knives, daggers, bowies — all legal.
Open carry: All knives are legal to open carry. No restrictions on type, mechanism, or blade length.
Concealed carry: This is where the "pocketknife" distinction matters.
- An "ordinary pocketknife" with a folding blade of 4 inches or less is not classified as a "knife" under § 571.010. It can be carried concealed virtually anywhere.
- A "knife" (anything else — including switchblades, daggers, large folders, and fixed blades) can be carried concealed in most places, but not in firearms-restricted areas listed under § 571.107.
The 2012 amendment removed switchblades from the list of prohibited weapons. The 2017 amendment narrowed the concealed carry restriction to only apply in areas where firearms are restricted — meaning you can carry a concealed knife (including an automatic) in most public places.
Under State v. Weir, a pocketknife must have a folding, single-edged blade to qualify as an "ordinary pocketknife." An automatic knife with a blade over 4 inches, or a double-edged blade, would be classified as a "knife" rather than a pocketknife.
OTF Knives in Missouri
OTF knives are legal to own and carry in Missouri. They fall under the statutory definition of "switchblade knife" — a knife that opens automatically by pressure applied to a button or device on the handle. Since switchblades were removed from the prohibited weapons list in 2012, OTFs are treated like any other legal knife.
For concealed carry: An OTF with a blade under 4 inches might qualify as an ordinary pocketknife if it has a single folding/retracting blade, potentially exempting it from the restricted-area prohibition. But given the mechanism involved, it's safer to treat any OTF as a "knife" under § 571.010 and avoid firearms-restricted locations.
Single-edge or double-edge — Missouri doesn't prohibit either. The distinction matters only for whether it qualifies as an "ordinary pocketknife" (it won't if double-edged, per State v. Weir).
Switchblades vs. Automatic Knives: What Missouri Considers Them
Missouri has a clear statutory definition of "switchblade knife" — any knife with a blade that folds into the handle and:
1. Opens automatically by button or device on the handle, OR 2. Opens by gravity or centrifugal force
This covers side-opening automatics, OTFs, button-release knives, and gravity knives. All are legal to own and carry in Missouri since the 2012 reform.
Assisted openers — knives that require manual force to initiate opening, with a spring assisting completion — are generally not considered switchblades and are not subject to the switchblade definition. They've always been legal in Missouri.
Carrying an Automatic Knife in Missouri
Open Carry
Fully legal. No restrictions on open carry of any knife type in Missouri, including automatic knives, switchblades, OTFs, fixed blades, and any other knife.
Concealed Carry
Legal in most places. The 2017 amendment to § 571.030 restricts concealed carry of "knives" (as defined — not ordinary pocketknives) only in areas where firearms are restricted under § 571.107. Those restricted areas are listed below.
Missouri also has robust constitutional carry laws for firearms, and the general legislative trend has been to expand, not restrict, concealed carry rights.
Important: Under State v. Rowe, a knife is considered "concealed" if it is "not readily and practically visible to approaching persons under ordinary circumstances." Even if part of the handle is visible, if it's not recognizable as a weapon, it may be deemed concealed.
Where You Can't Carry (Restricted Locations)
Under § 571.107, the following locations restrict firearms and, by extension under § 571.030, the concealed carry of "knives" (excluding ordinary pocketknives):
- Schools and school buses — § 571.030(1)(10)
- Government buildings occupied by federal, state, or local government
- Churches or places of worship — § 571.030(1)(8)
- Election precincts on election day
- Courthouses and law enforcement facilities
- Airports — passenger terminals (federal law also applies)
- Amusement parks, stadiums — if posted
Note: under § 571.030(3), these restrictions do not apply when weapons are transported in a "nonfunctioning state" or are "not readily accessible." A knife stored in a locked case in your vehicle trunk, for example, would likely be covered by this exception.
Concealed carry permit holders (§ 571.101–571.121) have additional exemptions for some restricted areas.
Blade Length Restrictions
Missouri does not impose a general blade length restriction on any knife. The 4-inch blade limit in § 571.010 only defines what qualifies as an "ordinary pocketknife" (exempt from the "knife" definition). It is not a carry prohibition.
You can own and carry a knife of any blade length in Missouri. You just can't carry a "knife" (blade over 4 inches, or dagger/dirk/stiletto) concealed into firearms-restricted areas.
What About Assisted Openers?
Assisted-opening knives are legal in Missouri. They are not classified as switchblades because they require manual initiation of the blade opening. Carry them freely — open or concealed.
Buying Automatic Knives in Missouri
You can purchase automatic knives and have them shipped to Missouri. We ship to all Missouri addresses. Missouri places no restrictions on the sale or purchase of automatic knives, switchblades, or OTFs.
Preemption
Missouri has strong state preemption for firearms. Under § 21.750 (the "Second Amendment Preservation Act" and related statutes), local governments are restricted from enacting firearms regulations more restrictive than state law.
For knives specifically, Missouri's preemption framework is less explicit. However, the practical effect of the 2012 and 2017 reforms — removing switchblades from prohibited weapons and narrowing concealed carry restrictions — establishes a permissive statewide baseline. Few if any local municipalities have enacted knife-specific restrictions beyond state law, but it's worth checking local ordinances in Kansas City, St. Louis, and Springfield.
Age Restrictions
Under § 571.030(1), the concealed carry restrictions apply to all persons. However, § 571.030(3) provides that the concealed carry restriction does not apply to persons 19 years or older (or 18 and a member or honorable discharge of the U.S. Armed Forces) transporting a concealable firearm in a motor vehicle. This exemption specifically addresses firearms and may not extend to knives.
Missouri does not set a specific minimum age for knife ownership in the general criminal code, but selling weapons to minors may be restricted under other provisions.
Recent Changes
- 2012: Missouri removes switchblades from the prohibited weapons list
- 2017: Missouri amends § 571.030 to restrict concealed carry only in firearms-restricted areas (previously applied more broadly)
- 2024: § 571.010 updated (H.B. 2287) — definition cleanup but no substantive changes to knife legality
Missouri's legislative trend is clearly toward expanded carry rights and fewer restrictions.
Frequently Asked Questions
Can I carry an OTF knife in Missouri?
Yes. OTF knives are legal to own, open carry, and conceal carry in Missouri. The only restriction is carrying one concealed into firearms-restricted areas (schools, courthouses, government buildings, churches, etc.).
Are switchblades illegal in Missouri?
No. Missouri removed switchblades from its prohibited weapons list in 2012. They are legal to own, carry openly, and carry concealed in most locations.
Is there a blade length limit for automatic knives in Missouri?
No general blade length limit exists. The 4-inch reference in § 571.010 only defines what qualifies as an "ordinary pocketknife" exempt from the "knife" definition — it's not a carry prohibition.
Legal Disclaimer
This article is for informational purposes only and does not constitute legal advice. Knife laws change — sometimes faster than websites update. Federal, state, and local laws may all apply to your situation, and local ordinances can be more restrictive than state law.
Before purchasing, carrying, or traveling with any automatic knife, OTF knife, or switchblade, verify current laws with official state and local sources. We are not attorneys, and we are not responsible for actions taken based on this information.
When in doubt, consult a licensed attorney in your jurisdiction.