Understanding the Legal Landscape of Pocket Knives in Idaho

Idaho is generally permissive regarding pocket knives and other types of knives. Most knives, including pocket knives, are legal to own and carry for law-abiding adults. There are no outright bans on specific knife types for general ownership or open carry.

Open Carry

Open carry of pocket knives is legal statewide for adults, regardless of blade length or type.
There are no restrictions on the open carry of knives in public, except in certain sensitive locations such as schools, courthouses, and correctional facilities.

Concealed Carry

Concealed carry of pocket knives with blades 4 inches or less is legal for adults without a permit.
For knives with blades longer than 4 inches (such as large folding knives or fixed blades), concealed carry is legal for adults 18+ who are not otherwise disqualified (e.g., felons, certain mental health adjudications).
Idaho’s “constitutional carry” law means that if you can legally possess a firearm, you can also carry a concealed knife, including larger blades, without a permit.

Restrictions and Sensitive Locations

Schools: Only pocket knives with blades less than 2.5 inches are allowed on K-12 school property and school buses.
Courthouses, jails, and certain government buildings: Knives are generally prohibited in these locations.
Minors: Minors under 18 may carry pocket knives, but written parental permission is required for larger blades.

Statewide Preemption

Idaho enforces statewide preemption for knife laws—local governments cannot enact their own knife restrictions that differ from state law, with limited exceptions for schools, courts, law enforcement facilities, and places of involuntary confinement.
This means knife laws are uniform across Idaho, reducing confusion for residents and travelers.

Intent and Use

Intent matters: Carrying a knife with the intent to use it unlawfully is a crime, regardless of type or size.
Using any knife in a threatening or criminal manner is illegal and can lead to prosecution.

Summary Table

Situation	Legal Status in Idaho
Open carry of pocket knives	Legal statewide
Concealed carry (blade ≤ 4″)	Legal for adults, no permit required
Concealed carry (blade > 4″)	Legal for adults 18+ (not disqualified)
On K-12 school property	Blade must be < 2.5″
In courthouses, jails, etc.	Prohibited
Local knife ordinances	Preempted by state law (with exceptions)

Key Takeaways

Pocket knives are broadly legal to own and carry in Idaho, both openly and concealed, for most adults.
Blade length and location matter: Restrictions apply in schools and certain government buildings.
State law overrides local ordinances, ensuring uniformity across Idaho.
Intent to use a knife unlawfully is always illegal, regardless of the knife’s size or type.

Always check the latest Idaho statutes or consult legal counsel if you have specific questions about your situation.

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