Idaho knife law is generally permissive. No broad statewide ban on ordinary knives was identified in the current statutes reviewed, open carry is generally lawful, and concealed carry is also broadly allowed under Idaho’s current weapons code. The main statewide limits involve school property, courthouses and secure facilities, intoxicated concealed carry, minors and specified sales to minors, plus a six-inch threshold that matters inside the concealed-weapons chapter. (Justia Law)
This article provides general legal information, not legal advice. (Justia Law)
Quick Answer
Idaho is one of the more permissive states for knives, but the details still matter in concealed carry, school-property, minor-possession, and sensitive-place rules. Idaho Code § 18-3302 defines “concealed weapon” and “deadly weapon,” excludes knives with blades of six inches or less from that chapter’s deadly-weapon definition, and broadly allows concealed carry for qualifying adults; other sections then add school-property limits, intoxication rules, minor-related rules, and sensitive-place restrictions. (Justia Law)
Most knives are generally lawful to own in Idaho. The current Idaho statutes reviewed do not indicate a broad statewide adult ownership ban on ordinary knives, and no separate statewide adult ban was identified for common folding knives, fixed blades, utility knives, or similar ordinary knife types. The more important Idaho questions are usually how the knife is carried, whether it falls within the concealed-weapons chapter, whether it is brought into a restricted place, and whether it is connected to criminal intent or threatening conduct. Idaho Code § 18-3301 and § 18-3303 still punish possession with intent to assault and threatening exhibition or unlawful use of a deadly weapon. (Justia Law)
Open carry is generally lawful in Idaho. Idaho Code § 18-3302(4)(a) provides that the concealed-weapons restriction does not apply to a deadly weapon located in plain view, which is why Idaho is commonly treated as an open-carry-friendly state for knives. That does not make every context safe, however: threatening display, unlawful use, schools, courthouses, jails, law enforcement facilities, and other secure settings can still create separate legal problems. (Justia Law)
Concealed carry is also broad in Idaho, but the statute’s definitions control the answer. Idaho Code § 18-3302 says a “concealed weapon” is a deadly weapon carried in a manner not discernible by ordinary observation, and the same section excludes any knife with a blade of six inches or less from that chapter’s definition of “deadly weapon.” For knives that do count as deadly weapons under the chapter, Idaho law broadly allows permitless concealed carry for qualifying adults over 18 who meet the statute’s citizenship or military and disqualification criteria, and it separately exempts any deadly weapon concealed in a motor vehicle. Idaho Code § 18-3302B also makes it unlawful to carry a concealed weapon while intoxicated or under the influence. (Justia Law)
Idaho Code § 18-3302C then adds sensitive-place limits for concealed weapons. Under that section, a person carrying under Idaho’s concealed-weapons framework may not carry a concealed weapon in a courthouse, juvenile detention facility or jail, or a public or private school except for the listed exceptions. (Justia Law)
The current statutes reviewed do not identify automatic knives, switchblades, butterfly knives, or double-edged knives as separately prohibited adult possessions statewide. Idaho’s current knife-law structure focuses more on the concealed-weapons definitions in Idaho Code § 18-3302, sensitive-place rules such as Idaho Code § 18-3302C and § 18-3302D, and local preemption under Idaho Code § 18-3327 than on separate named bans for those knife styles. For double-edged knives, the practical issue is whether a particular knife is treated as a dagger or other deadly weapon in context, not a standalone statewide ownership ban identified in the reviewed statutes. (Justia Law)
No general statewide maximum blade-length cap was identified, but blade length still matters in Idaho law. First, Idaho Code § 18-3302 excludes any knife with a blade of six inches or less from that chapter’s definition of “deadly weapon,” which is an important concealed-carry threshold. Second, Idaho Code § 18-3302D adopts the federal dangerous-weapon definition in 18 U.S.C. § 930 for school-property purposes, and that federal definition excludes a pocket knife with a blade of less than 2½ inches. So Idaho does not appear to impose a single all-purpose statewide blade limit, but six inches and 2½ inches both matter in specific legal settings. (Justia Law)
Yes. Schools and certain secure government facilities are the main state-law problem areas. Idaho Code § 18-3302D makes it unlawful to possess a firearm or other deadly or dangerous weapon on school property, in school-used buildings or structures, or on school-provided transportation, subject to listed exceptions. Idaho Code § 18-3302C also bars concealed weapons in a courthouse, juvenile detention facility or jail, and in public or private schools except as allowed by the statute. (Justia Law)
Idaho’s 2024 knife-preemption law does not erase every local or facility-level restriction. Idaho Code § 18-3327 expressly allows regulation of knife possession by public schools, courts for courthouses, law enforcement facilities, places of involuntary confinement including prisons and jails and certain state-managed entities, and local rules tied to child care facility safety standards. Federal buildings and federal court facilities are separate again under 18 U.S.C. § 930. (Justia Law)
Yes, but Idaho’s minor-related rules are narrower than a blanket ban on all knives. Idaho Code § 18-3302A makes it a misdemeanor to sell a “weapon” to a minor under 18 without written parental or guardian consent, and that section defines “weapon” to include a dirk, dirk knife, bowie knife, dagger, pistol, revolver, or gun. Idaho Code § 18-3302E similarly says a person under 18 may not possess a weapon as defined in § 18-3302A unless the minor has written parental permission or is accompanied by a parent or guardian; a minor under 12 must be accompanied by an adult. (Justia Law)
That means Idaho does have age-related rules for specified knives such as dirks, bowie knives, and daggers. The reviewed statutes do not show a broad, one-size-fits-all statewide age ban covering every ordinary pocketknife or work knife. (Justia Law)
Yes. Idaho now has statewide knife-law preemption. Idaho Code § 18-3327, added by 2024 House Bill 620, says that except as provided in Idaho Code § 18-3302 and § 18-3302A, a city, county, or other political subdivision may not enact ordinances, rules, or taxes relating to the transportation, possession, carrying, sale, transfer, purchase, gift, devise, licensing, registration, or use of a knife or knife-making components in Idaho. The official Idaho Legislature bill page shows H.B. 620 was signed on March 28, 2024, as Session Law Chapter 221, effective July 1, 2024. (Justia Law)
Far less than before July 1, 2024. Because Idaho Code § 18-3327(4) says conflicting local rules are null, void, and of no force and effect, ordinary city or county knife ordinances are no longer the main issue in Idaho. The remaining local or facility-specific exceptions are the ones expressly preserved by statute, especially schools, courthouses, law enforcement facilities, places of involuntary confinement, and child care facility safety standards. (Justia Law)
Federal law is separate from Idaho law and still matters in a few knife-specific situations. The Federal Switchblade Act, 15 U.S.C. §§ 1241-1245, addresses switchblade knives in interstate commerce and certain federal jurisdictions, and federal law separately addresses ballistic knives. Federal facility law, 18 U.S.C. § 930, also matters on federal property and in federal court facilities. (U.S. Code)
Mailing rules matter too. Under 18 U.S.C. § 1716, knives that open automatically by button, inertia, gravity, or both are generally nonmailable except as allowed by law, and USPS Publication 52 gives the postal rules that implement those mailing limits. So even though Idaho state law is relatively permissive, federal mailing and federal-property rules can still create separate restrictions. (U.S. Code)
Idaho is generally knife-friendly, but the safest short reading is this: ordinary knife ownership is broadly lawful, open carry is generally lawful, and concealed carry is also broad under current Idaho law. The real trouble spots are school property, courthouses and other secure facilities, intoxicated concealed carry, minor-related rules for specified weapons, and the six-inch and 2½-inch thresholds that appear in different parts of the law. Statewide knife preemption is now in place, so ordinary city-by-city knife ordinances matter far less than they did before July 1, 2024. (Justia Law)
| Issue | Idaho law |
|---|---|
| Knife ownership | No broad statewide adult ownership ban on ordinary knives was identified in the reviewed statutes. |
| Open carry | Generally lawful. A deadly weapon in plain view is outside the concealed-weapons restriction. Idaho Code § 18-3302(4)(a). |
| Concealed carry | Broadly allowed, but the statutory definitions matter. Idaho Code § 18-3302 excludes knives with blades of six inches or less from that chapter’s “deadly weapon” definition, and qualifying adults may broadly carry concealed deadly weapons without a license. Intoxicated concealed carry remains unlawful under Idaho Code § 18-3302B. |
| Automatic / switchblade / butterfly knives | No separate statewide adult ban on these knife types was identified in the reviewed Idaho statutes. Sensitive-place and concealed-carry rules may still matter depending on the knife and context. |
| Blade length | No general statewide maximum blade length was identified. The main thresholds are six inches in Idaho Code § 18-3302 and less than 2½ inches for the school-property exception incorporated through 18 U.S.C. § 930. |
| Restricted places | School property is restricted by Idaho Code § 18-3302D. Concealed weapons are restricted in courthouses, juvenile detention facilities or jails, and schools by Idaho Code § 18-3302C. Public schools, courthouses, law enforcement facilities, prisons or jails, and certain child care safety rules are also preserved exceptions under Idaho Code § 18-3327. |
| Minors / sales | Selling a dirk, dirk knife, bowie knife, or dagger to a minor under 18 without written parental or guardian consent is unlawful. Minor possession rules also apply to those specified weapons. Idaho Code §§ 18-3302A, 18-3302E. |
| Preemption | Yes. Idaho Code § 18-3327 broadly preempts local knife regulation. H.B. 620 was signed March 28, 2024, and took effect July 1, 2024. |
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The main recent enacted Idaho knife-law change identified in the reviewed sources is House Bill 620 from 2024. It added Idaho Code § 18-3327, created statewide knife preemption, was signed on March 28, 2024, and took effect July 1, 2024. (legislature.idaho.gov)
As of March 20, 2026, House Bill 621 had been introduced to revise Idaho Code § 18-3302C’s prohibited-conduct language, but the bill was only reported printed and referred to House State Affairs on February 11, 2026. It was not in force as of that date. (LegiScan)
Generally yes. No broad statewide adult ownership ban on ordinary pocket knives was identified, and Idaho Code § 18-3302 excludes knives with blades of six inches or less from that chapter’s “deadly weapon” definition. School-property rules are stricter because Idaho Code § 18-3302D incorporates 18 U.S.C. § 930’s dangerous-weapon definition, which excludes only a pocket knife with a blade of less than 2½ inches. (Justia Law)
The current Idaho statutes reviewed do not indicate a general statewide adult ban on switchblades. Federal law can still matter, though, especially the Federal Switchblade Act and mailing restrictions. (Justia Law)
Generally yes. Idaho Code § 18-3302(4)(c) says the concealed-weapons restriction does not apply to any deadly weapon concealed in a motor vehicle. Separate problems can still arise in restricted places such as school property or secure facilities. (Justia Law)
No general statewide maximum blade limit was identified. The two important thresholds are six inches in Idaho Code § 18-3302 and less than 2½ inches in the school-property framework tied to 18 U.S.C. § 930. (Justia Law)
Generally no. Since July 1, 2024, Idaho Code § 18-3327 has broadly preempted local knife regulation and makes conflicting local rules void, but the statute preserves certain exceptions for schools, courthouses, law enforcement facilities, places of involuntary confinement, and child care safety standards. (Justia Law)
Yes. Idaho’s preemption statute expressly allows public schools, including public charter schools, to regulate knife possession, and Idaho Code § 18-3302D separately restricts weapons on school property. (Justia Law)
Laws can change, local rules may still apply in the limited places Idaho allows, and restricted places, intent, intoxication, and prohibited status can all affect whether a knife is lawful in a specific situation. (Justia Law)
Official Idaho sources
Official federal sources
Optional secondary sources used for access and cross-checking