Missouri Knife Laws
Missouri’s number is four inches. An ordinary pocketknife at or under four inches goes almost anywhere concealed, and since 2012 an automatic knife of that size counts as an ordinary pocketknife. Any other blade is barred from seventeen listed places unless you hold a concealed carry permit. There is no statewide preemption, so a city or county may add its own rule.
This is not legal advice, and we are not lawyers. It is a plain reading of published summaries and the statutes they cite, kept current on a fixed schedule. Local ordinances are frequently stricter than state law and are not all captured here. Check the statute, and check your city, before you carry.
Missouri knife law at a glance
| Concealed carry blade limit | Four inches. An ordinary pocketknife at or under four inches goes almost anywhere concealed. Any other blade is barred from seventeen listed places, and a concealed carry permit lifts those place limits. |
|---|---|
| Automatic and switchblade knives | Legal since 2012, and an automatic with a blade of four inches or less counts as an ordinary pocketknife. |
| Knife types banned outright | None outright. |
| Statewide preemption | No. A city or county may write its own knife rule. |
| The statutes | Missouri Revised Statutes 571.010, 571.020, 571.030 and 571.107 — read them |
Source last revised 22 May 2021
Next review 15 November 2026
How fresh this is, and how you can tell
Two dates sit above, and they are not the same thing. Checked by us is the last time a person went back to the sources and confirmed this page still matches them. Source last revised is when the American Knife and Tool Institute last updated its own Missouri page. A 2021 revision date is not automatically wrong — it usually means nothing has changed since — but it does mean nobody had looked recently, and that is exactly the gap this page exists to close.
Crossing the Missouri state line
Knife law stops at the border and the next state does not have to agree with this one. If you drive, these are the states you are most likely to carry into, and what changes when you do.
| State | Automatic knives | Concealed blade limit |
|---|---|---|
| Iowa | Legal | Five inches. A dagger, razor, stiletto, switchblade or any knife with a blade over five inches is a dangerous weapon and may not be carried concealed. |
| Illinois | Legal with conditions | No statewide blade length. Chicago bars any knife with a blade longer than two and a half inches. |
| Kentucky | Legal with conditions | No blade length governs from 21, or with a concealed weapon license. Open carry is unrestricted. Kentucky courts have never drawn a clean line on what counts as an ordinary pocketknife, and one jury treated a five to six inch blade as a deadly weapon, so carry conservatively. |
| Tennessee | Legal | No blade length governs and concealment is not an issue. |
| Arkansas | Legal | Concealment is not the test. Arkansas defines a knife as any bladed hand instrument three inches or longer, and the offense is carrying one with intent to use it unlawfully. The three inches is part of the definition, not a carry limit. |
| Oklahoma | Legal | No blade length governs and concealment is not an issue. |
| Kansas | Legal | No blade length governs. You may carry a knife concealed or not, at any length. |
| Nebraska | Legal | Three and a half inches. Any dagger, dirk, knife or stiletto with a blade over three and a half inches may not be carried concealed. |
A knife that is lawful in your pocket at home can be unlawful the moment you cross, and nobody stops you at the line to tell you. The map for all fifty states covers the rest.
Common questions about Missouri knife laws
What size knife is legal to carry in Missouri?
Four inches. An ordinary pocketknife at or under four inches goes almost anywhere concealed. Any other blade is barred from seventeen listed places, and a concealed carry permit lifts those place limits.
Are switchblades legal in Missouri?
Legal since 2012, and an automatic with a blade of four inches or less counts as an ordinary pocketknife.
Which knives are banned outright in Missouri?
None outright.
Does Missouri have knife preemption?
No. Missouri has no statewide preemption, so a city or county can be stricter than the state code, and several are. Check your local ordinance as well as the statute.
Can I keep a knife in my car in Missouri?
Where a state has a concealed carry limit, a knife in a glovebox or a door pocket is generally treated as concealed. Read the concealed line above and apply it to the vehicle. If that line says concealment is not the issue in this state, the vehicle is not the issue either — but where you drive to still is, because schools and courthouses are barred everywhere.
Where this comes from
Two independent sources, cross-checked against each other, and the statute text where they disagree. The automatic knife column is the American Knife and Tool Institute’s state automatics table, checked against Knife Rights’ own switchblade legality table and their legislative update log. Everything on a state page is quoted or closely tracked from that state’s AKTI page, and we print the date AKTI last revised it so you can see for yourself how fresh the underlying work is.
Where a source is older than a change we know about, we say so on the page rather than quietly leaving the old answer up. That is the whole reason this is checked every two months.
Elsewhere on Popular EDC
The knife law map for all fifty states, the knife steel comparison chart for choosing the blade itself, and every Popular EDC tool in one place.
Data updated September 2026. Missouri knife law checked against the published sources on 15 September 2026, and due for review again on 15 November 2026.