Are Butterfly Knives Legal in Montana? (2026)
Yes — Butterfly Knives are legal in Montana as of 2026.
Quick Answer
Butterfly knives are legal to own and carry in Montana with no specific restrictions beyond general knife laws. The most significant recent change was the passage of a state preemption law, which nullified all local knife ordinances.
- Age restriction: 18+ for purchase
What the Law Says
Montana has state preemption for knife laws, meaning local governments cannot enact stricter ordinances. There are no state-level restrictions.
— Mont. Code Ann. § 45-8-361
| Category | Details |
|---|---|
| Possession | Legal |
| Sale & Purchase | Legal |
| Penalties | N/A |
| Age Restriction | 18+ for purchase |
| Pending Legislation | None known |
The most significant recent change was the passage of a state preemption law, which nullified all local knife ordinances.
Enforcement Reality
Montana has state preemption for knife laws, meaning local governments cannot enact stricter ordinances. Enforcement is minimal for all types of knives.
A common mistake is being unaware of the state preemption, leading to confusion about local regulations that are no longer valid.
Local Exceptions
None identified. State law applies uniformly across Montana. Local ordinances may still vary — check with your city or county government for any additional rules.
Real-World Scenarios: Butterfly Knives in Montana
Can You Fly With Butterfly Knives Out of Montana?
Butterfly Knives may be legal in Montana, but airports are federal territory. TSA screens under federal rules, not state law. If the item is federally restricted, expect problems at the checkpoint. Even if it clears TSA, the laws of your destination state apply the moment you land. Plenty of travelers have learned this the hard way — legal when they packed, criminal when they arrived.
Bottom Line
Butterfly Knives are legal in Montana. You can carry them without violating state law, though federal rules and local ordinances may still apply. Always verify current law before acting.
Montana vs. the Rest of the US
Across the US, carrying a butterfly knife is fully legal in 39 states, restricted in 10, and illegal in 1. Montana falls in the LEGAL category.
View the full 50-state map →Reviewed by cross-referencing the cited state statute against current legislative databases and regulatory publications.
Sources & Verification
This page was reviewed by Ethan Harper by comparing the legal status against the cited state statute. AllowedHere is an informational resource and does not provide legal advice. Consult a licensed attorney for guidance specific to your situation.
Comprehensive Montana Legal Guides
Explore all related legal topics in Montana — statutes, penalties, and enforcement in one place.