Knife Laws in California: What’s Legal? [2023]

When it comes to owning a weapon of any kind, California’s arguably the strictest state in the union. California knife laws can be ambiguous, and purposefully so: They’re often written to discourage residents from engaging in legal acts the state legislature knows it would have a difficult time outlawing.

California Knife Laws to Know in 2023

NOTE: This guide is not legal advice, and Knife Know-It-All does not provide legal counsel. If you’re uncertain about any California knife laws, contact a local attorney.

Q: What Knifes are Illegal in California?

A: These weapons are illegal to manufacture, import, sell, or possess, and they include certain knives:

  • Air Gauge Knife
  • Ballistic Knife
  • Belt Buckle Knife
  • Cane Sword
  • Concealed Dirk or Dagger
  • Lipstick Case Knife
  • Shobi-Zue (A blade concealed within a wood staff)
  • Shuriken (Commonly called Throwing Stars)
  • Writing Pen Knife

California Penal Code 16590 lists all prohibited weapons.

Q: Are Knife Blade Lengths Restricted in California?

A: Generally, there is no maximum blade length for knives in California. But there are restrictions on the length of switchblades, and it is illegal to carry knives with blades over a certain length in certain public places and on school grounds:

  • It is illegal to possess any knife with a longer than 2-1/2″ on school grounds.
  • It is illegal to possess a fixed blade longer than 2-1/2″ on university grounds.
  • It is illegal to openly carry a knife with a blade longer than 3″ in Los Angeles.
  • It is illegal to possess a switchblade with a blade measuring 2″ or longer.

A: Yes, switchblades are legal to possess in California, but the blade must be shorter than than 2 inches.

California Penal Code 17235 defines a switchblade as:

“[A] knife having the appearance of a pocketknife and includes a spring-blade knife, snap-blade knife, gravity knife, or any other similar type knife, the blade or blades of which are two or more inches in length and which can be released automatically by a flick of a button, pressure on the handle, flip of the wrist or other mechanical device, or is released by the weight of the blade or by any type of mechanism whatsoever.“

California Penal Code 21510 defines the “two-inch” switchblade rule:

“Every person who does any of the following with a switchblade knife having a blade two or more inches in length is guilty of a misdemeanor:

  • (a) Possesses the knife in the passenger’s or driver’s area of any motor vehicle in any public place or place open to the public.
  • (b) Carries the knife upon the person.
  • (c) Sells, offers for sale, exposes for sale, loans, transfers, or gives the knife to any other person.“

A: No. It is illegal to possess a butterfly knife in California. The California Court of Appeals effectively outlawed butterfly knives by overturning a case ruling in 1989. We cover this in more detail in our Guide to Butterfly Knife Laws.

Q: Can I Carry a Concealed Knife in California?

A: Yes. Folding knives with a blade of any length may be carried concealed, except in Los Angeles and on school property. You cannot carry any of the prohibited weapons described in Penal Code 16590. You cannot conceal and carry a switchblade with a blade 2″ or longer. Fixed blades cannot be carried concealed. Fixed blades include dirks, daggers, kitchen knives, ice picks, and any other fixed-blade or sharp object that can readily be used as a stabbing weapon. You cannot carry any concealed weapon in Los Angeles, per City Code Sec. 55.01.

Remember, it’s also illegal to carry a folding knife with a blade longer than 2-1/2″ on school grounds, and you can’t possess a fixed blade longer than 2-1/2″ on university grounds.

A: Yes, but you should be cautious possessing one. Penal Code 17235 (the same section that defines switchblades) exempts spring-assisted knives only if they meet the following definition:

“‘Switchblade knife’ does not include a knife that opens with one hand utilizing thumb pressure applied solely to the blade of the knife or a thumb stud attached to the blade, provided that the knife has a detent or other mechanism that provides resistance that must be overcome in opening the blade, or that biases the blade back toward its closed position.“

The exemption is vague, and any law enforcement officer or court could easily decide your spring-assisted knife is, in fact, a switchblade. It’s better to air on the side of caution, here.

Q: Can I Open Carry a Knife in California?

A: Yes. Fixed blades (like dirks and daggers) must be carried openly in a sheath. Although it is legal to openly carry a knife in California, we recommend avoiding the practice in general public. Penal Code 417 says it is a misdemeanor to “draw or exhibit any deadly weapon whatsoever, in a rude, angry, or threatening manner,” punishable by imprisonment for a minimum of 30 days.

Q: Can I use a Knife for Self-Defense in California?

A: Yes, but force can only be used in self-defense when reasonably necessary. That means you must have a reasonable belief that you are in imminent and immediate danger of being physically harmed or killed. You may only use the amount of force necessary to defend against that danger. California’s self-defense laws are not specific in describing what amount of force may be reasonable, nor when force may be reasonable. You must decide that and, if law enforcement charges you with a crime for using a knife or deadly force to defend yourself, a jury will decide if you acted reasonably.