Is Butterfly Knives Legal in Montana? (2026)

Confidence: High

Yes — Butterfly Knives are legal in Montana as of 2026.

Key Restriction
Age restriction: 18+ for purchase
Penalty
None
Last Updated
2026-03-25
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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.

Key Conditions & Exceptions:
  • 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
Recent Changes

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.

Charge Level
No criminal penalty.
Enforcement Likelihood
Very Low
Common Triggers
Use of the knife in a crime.
Common Mistakes

A common mistake is being unaware of the state preemption, leading to confusion about local regulations that are no longer valid.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.

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 →

Neighboring States

Laws change at state lines. Here is how bordering states compare on Butterfly Knives:

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Frequently Asked Questions

Is it legal to carry Butterfly Knives in Montana?
Yes — Butterfly Knives are legal in Montana as of 2026. 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.
Can you carry a butterfly knife in Montana?
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.
What is the age restriction for carrying a butterfly knife in Montana?
18+ for purchase

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EH
Ethan Harper Independent Legal Researcher

Reviewed by cross-referencing the cited state statute against current legislative databases and regulatory publications.

Last reviewed: 2026-03-25 Method: Statute cross-reference

Sources & Verification

1.
Primary Citation
2.
Statute Summary
Montana has state preemption for knife laws, meaning local governments cannot enact stricter ordinances. There are no state-level restrictions.
Verified: 2026-03-25 Reviewed by: Ethan Harper Method: Statute cross-reference Confidence: High

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.

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