Cook County gun laws stack county ordinances on top of Illinois state law, producing one of the strictest regulatory environments in the country. If you live in or move to the county with a firearm, you have to satisfy both sets of rules at once, and when they conflict the stricter one controls. Illinois does not preempt local firearm regulation, so the county’s home-rule ordinances carry real weight alongside state statutes.
You Need a FOID Card First
Before you can own a firearm or buy ammunition anywhere in Illinois, including Cook County, you need a Firearm Owner’s Identification card from the Illinois State Police.1Illinois State Police. Firearm Owner’s Identification The card costs $10 and lasts 10 years.2Illinois State Police Firearms Services Bureau. FOID Card FAQ The authority comes from the Firearm Owners Identification Card Act.3Illinois General Assembly. 430 ILCS 65
Applicants must be at least 21. If you’re younger, a parent or legal guardian has to sponsor you with a notarized affidavit; a spouse or sibling cannot. Active-duty military under 21 may qualify for a waiver.2Illinois State Police Firearms Services Bureau. FOID Card FAQ A background check is part of every application, and the State Police will deny anyone with a felony conviction, a domestic battery conviction (felony or misdemeanor), an active order of protection, or a narcotics addiction, among other disqualifiers.1Illinois State Police. Firearm Owner’s Identification
Buying a Firearm in Cook County
Every firearm purchase in Illinois carries a 72-hour waiting period that starts when buyer and seller agree to the sale. The rule applies to handguns, rifles, and shotguns, and to both dealer and private transactions.4Illinois State Police. FOID/CCL Card Verification Portal
At a licensed dealer, you complete ATF Form 4473, show government ID, and the dealer runs a NICS background check. For a private sale where neither party is a licensed dealer, the seller has to route the transfer through a licensed dealer or contact the Illinois State Police directly to verify the buyer’s FOID.4Illinois State Police. FOID/CCL Card Verification Portal
The County Firearm and Ammunition Tax
Cook County adds its own $25 tax on every retail firearm sale within the county, and taxes ammunition separately.5Cook County Government. Firearm and Firearm Ammunition Tax Retailers inside the county collect and remit the tax under Sections 74-665 through 74-675 of the Cook County Code. Dealers in surrounding counties aren’t subject to it, which is why shops just outside the county line attract Cook County buyers.
What’s Banned: Assault Weapons and Large-Capacity Magazines
Two bans operate at once. The county’s Blair Holt Assault Weapons Ban applies within unincorporated Cook County and participating municipalities. The Protect Illinois Communities Act (PICA) applies statewide and took effect in January 2023. You have to comply with whichever one is stricter on a given point.
The county ordinance restricts firearms by a list of prohibited models and by physical features. Semiautomatic rifles or pistols with features like folding or telescoping stocks, protruding pistol grips, or flash suppressors fall within the ban. Any magazine that holds more than 10 rounds is prohibited. A first violation runs $1,000 to $5,000 and up to six months in jail; repeat violations can reach $10,000.6Cook County Government. U.S. District Court Upholds Cook County’s Assault Weapon Ban If you already own a prohibited magazine, you must remove it from the county or surrender it to law enforcement.
PICA bans the manufacture, sale, purchase, and possession of over a thousand models of semiautomatic firearms and accessories like flash suppressors and grenade launchers. Its magazine limits are 10 rounds for long guns and 15 for handguns.7Illinois General Assembly. 720 ILCS 5/24-1.9 People who lawfully owned covered items before PICA may keep them under a grandfathering provision, but new acquisitions are off the table.
For a Cook County handgun owner, the county’s 10-round cap controls, because it’s tighter than PICA’s 15-round handgun limit. Before buying any semiautomatic firearm or magazine, check both the county ordinance and the state statute. Either can independently make possession a crime.
Safe Storage at Home
The Blair Holt Firearm Storage Act, at Section 54-183 of the Cook County Code, requires every firearm in a residence to be stored so that nobody under 21 and nobody legally prohibited from possessing firearms can get to it. A locked container, gun safe, or trigger lock satisfies the rule. A high shelf or an unlocked drawer does not.
Enforcement generally comes after the fact. If an unsecured firearm is used in a crime or causes an accidental injury, the registered owner faces administrative fines and potential criminal liability regardless of who pulled the trigger.
Concealed Carry Rules
Illinois issues concealed carry licenses statewide under the Firearm Concealed Carry Act,8Illinois General Assembly. 430 ILCS 66 but the list of places you can’t carry is long enough that staying legal in Cook County takes active attention.
Getting a Concealed Carry License
An Illinois CCL requires 16 hours of approved firearms training, a background check, and a $150 fee for residents ($300 for non-residents).2Illinois State Police Firearms Services Bureau. FOID Card FAQ The license lasts five years, and renewal takes three additional hours of training.
Where You Cannot Carry
Even with a valid license, state law bars concealed carry in a long list of sensitive locations, including:
- Any building controlled by executive or legislative branch officers, or by a unit of local government
- Any building housing circuit, appellate, or supreme court matters
- Buses, trains, and any transportation paid for with public funds, plus transit stations and parking areas
- Public parks, athletic areas, and playgrounds under municipal or park district control
In a county with the CTA, Metra, dozens of courthouses, and hundreds of parks, those categories cover a lot of ground. Private businesses can also ban firearms by posting an Illinois State Police-approved sign measuring four inches by six inches at every entrance.10Illinois State Police Firearms Services Bureau. Requirements for Concealed Carry Signage Carrying in a posted business or any prohibited area can mean license revocation and criminal charges.
The Gun Offender Registry
Under Section 54-250 of the Cook County Code, people convicted of certain firearm offenses within the county must register with the Cook County Sheriff’s Office, providing a current address, a photograph, and details about the weapon involved. Registrants renew annually for four years from initial registration. The obligation ends after four years without a new qualifying conviction. Failing to register or giving false information is a separate offense with its own fines and possible jail time.
Federal Rules That Still Apply
Federal law adds a layer that occasionally surprises Cook County owners.
NFA Items
The National Firearms Act controls machine guns, short-barreled rifles and shotguns (barrels under 18 inches), silencers, and destructive devices. Each requires ATF registration and a $200 tax per item.11ATF. National Firearms Act Federal registration does not override Illinois law, so items Illinois bans outright remain illegal in Cook County even with proper federal paperwork. Civilian ownership of machine guns manufactured after 1986 is federally prohibited.
Flying Out of O’Hare or Midway
TSA requires any firearm in checked baggage to be unloaded and locked in a hard-sided container. You must declare it at the airline ticket counter at check-in. Ammunition can go in checked bags in its original packaging or a container designed for it. Neither firearms nor ammunition are allowed in carry-on bags.12Transportation Security Administration. Transporting Firearms and Ammunition Legal possession in Illinois says nothing about whether you can possess the firearm at your destination, so check the laws where you’re landing before you pack.