Idaho generally allows adults to own and carry common knives. Its concealed-weapons statute expressly excludes any knife with a blade six inches or shorter from the term “deadly weapon.” Eligible people age 18 or older may also carry a concealed deadly weapon without a license, subject to the statute’s qualifications and prohibited-place rules. [1] [2]
The six-inch figure is an exclusion from Idaho’s concealed-deadly-weapon definition. It is not a general state ban on owning or openly carrying every longer knife.
What knives may you own in Idaho?
Idaho does not impose a general state ban on adult ownership of ordinary pocketknives, fixed blades, automatic knives, OTF knives, dirks, daggers, Bowie knives, or balisongs. Ownership does not authorize threatening use, criminal conduct, or possession in a prohibited place.
How does Idaho define a concealed deadly weapon?
Idaho Code § 18-3302 defines a concealed weapon as a deadly weapon carried on or about the person in a manner not discernible by ordinary observation. “Deadly weapon” includes a dirk, dirk knife, Bowie knife, dagger, firearm, and other instruments designed or intended to be readily capable of causing death or serious bodily injury. [1]
The same section excludes knives intended for food processing, preparation, or eating and any knife with a blade six inches or shorter. A common pocketknife within that limit is therefore outside this particular concealed-deadly-weapon definition.
May you openly carry a knife?
Idaho does not impose a general state permit requirement for open carry of lawful knives. Open carry does not authorize threatening display, assault, disorderly conduct, trespass, or possession at a school or another prohibited location.
May you carry a longer knife concealed without a license?
The Idaho Attorney General states that a person may carry a concealed weapon without a license if the person is at least 18, is a United States citizen or current member of the United States Armed Forces, and is not otherwise disqualified from receiving a concealed-weapons license for a reason other than being under 21. [2]
This permitless authority can apply to a qualifying concealed knife longer than six inches or another knife classified as a deadly weapon. People who do not meet every requirement should not assume permitless carry is available.
Are automatic knives prohibited?
Idaho does not impose a general state ban on automatic or OTF knives merely because of the opening mechanism. The concealed-carry analysis still depends on blade length, classification, carrier eligibility, and location. Federal commerce and shipping rules may also apply.
What rules apply at schools?
Idaho Code § 18-3302D restricts possession of firearms and other deadly or dangerous weapons on school property, at covered school-sponsored activities, and on school-provided transportation, subject to statutory definitions and exceptions. It can also apply to students at school-sponsored activities away from campus. [3]
A small pocketknife is not automatically a weapon under every part of the statute, but intent, use, school policy, and federal definitions matter. Practical rule: do not bring any knife to a school, school bus, or school activity without clear written authorization.
What vehicle and restricted-place rules matter?
The Idaho Attorney General states that a person may carry a deadly weapon concealed in a vehicle, including a loaded or unloaded firearm, without a concealed-weapons license. [2]
Keep any knife closed or sheathed and secured against movement. Courthouses, detention facilities, schools, certain state facilities, employers, and private property may impose separate restrictions.
Can local and private rules be different?
Idaho’s strongest weapons-preemption statutes focus on firearms rather than establishing an equally broad knife-specific rule. Check current city and county codes, particularly for parks, public buildings, events, and other locally controlled property.
Businesses, employers, venues, and property owners may prohibit knives as a condition of entry or employment.
What air-travel rules apply?
The Transportation Security Administration prohibits knives in carry-on baggage except for plastic or round-bladed butter knives. Checked-baggage and airline requirements still apply. [4]
What should you verify before carrying?
- Whether the blade is six inches or shorter and excluded from the concealed-deadly-weapon definition.
- Whether the design is a dirk, dirk knife, Bowie knife, dagger, or other deadly weapon.
- Whether the carrier satisfies every permitless-carry requirement.
- Whether the destination is a school, courthouse, detention facility, employer, venue, or private property with stricter rules.
- Whether a local ordinance or another state’s law applies.
Conclusion
Idaho generally permits common knives and excludes blades six inches or shorter from its concealed-deadly-weapon definition. Eligible people age 18 or older may carry concealed deadly weapons without a license, but school rules, restricted locations, local codes, private policies, and conduct remain important.
Last reviewed: August 24, 2026.
This article provides general information, not legal advice. Knife laws and their interpretation can change and may depend on blade measurement, design, eligibility, carry method, location, local ordinance, and conduct. Verify current law through official sources or consult a qualified Idaho attorney about a specific situation.
Sources & References
- [1] Idaho Code § 18-3302. Concealed-weapon definitions, six-inch knife exclusion, permitless carry, licenses, and exceptions.
- [2] Idaho Office of the Attorney General — Concealed Weapons. Official guidance on permitless carry, covered weapons, eligibility, vehicles, and exceptions.
- [3] Idaho Code § 18-3302D. Weapons on school property, school transportation, school-sponsored activities, definitions, and exceptions.
- [4] Transportation Security Administration — Knives. Federal carry-on and checked-baggage guidance.
