Is Weed Legal in Illinois or Not?


I thought marijuana was legal …can I still be arrested?

As of January 1, 2020, the State of Illinois signed a law that allows adults, 21 years of age and older, to purchase cannabis products for medical and recreational use from licensed dispensaries in Illinois. However, don’t let this law fool you! Legalizing marijuana is NOT a free pass to use all forms of cannabis when and wherever you’d like. Illinois has many rules and regulations that prohibit the purchase, possession, and transportation of cannabis, such that you may unknowingly violate the law and potentially get arrested, if you’re not extra careful!

Like most laws, the legalization of cannabis is much more limiting than many people realize. This article is designed to help you understand the basic cannabis laws in Illinois so that you can make better informed decisions and avoid the risk of criminal charges or even arrest.

Can I Purchase Cannabis?

Adults, 21 years of age and over, with proof of valid government identification can legally purchase cannabis in the state of Illinois.

Where Can I Get Cannabis?

Cannabis can be legally acquired in Illinois in only one of two ways:

  1. purchasing it from a dispensary, or
  2. cultivating it within your own home.

The first way to acquire cannabis legally in Illinois is by purchasing it. But to do so legally, cannabis MUST be purchased by paying with cash from an Illinois licensed dispensary with valid government identification. This is true for all cannabis whether intended for medicinal purposes OR for recreational purposes. This means that NO amount of cannabis can be legally purchased from anyone outside of a licensed dispensary.

In other words, if you buy weed from this guy, you’re in danger of getting arrested:


The second legal method to acquire cannabis is much more limiting. Illinois residents, 21 years of age and older, can cultivate and grow their own cannabis plants, as long as they are registered as a participant in the Compassionate Use of Medical Cannabis Pilot Program. The resident MUST live in a household that they own or have permission from the homeowner to cultivate cannabis within the residence.

Additionally, there is a limit on the amount of cannabis that can be grown at any one time. Under Illinois law, no one can cultivate more than 5 plants at a time that measure 5 inches or taller. And reasonable precautions MUST be made to prevent access from unauthorized individuals from accessing the cannabis plants.

How Much Cannabis Can I Get?

How much cannabis an individual can purchase and possess varies depending on whether they are an Illinois resident or a non-Illinois resident.

For Illinois residents, an individual can legally purchase and possess 30 grams of cannabis flower (about an ounce), 5 grams of cannabis concentrate, and no more than 500 milligrams of THC contained in cannabis-infused products cumulatively.

Additionally, Illinois residents who participate in the Compassionate Use of Medical Cannabis Pilot Program can possess more than 30 grams of cannabis as long as it is grown and properly secured within their residence.

Non-Illinois residents can possess cannabis legally as long as cumulatively they possess no more than 15 grams of cannabis flower, 2.5 grams of cannabis, and no more than 250 milligrams of THC contained in cannabis-infused products.

Non-citizens of the United States cannot possess, grow, or use cannabis as it is against Federal Law without the risk of being deported. Therefore, whenever charged with any criminal or traffic offense, non-citizens should consult an experienced criminal lawyer in order to properly defend themselves and avoid immigration consequences.

Where Can I Smoke Cannabis?

Cannabis can only be smoked, vaped, or consumed in the confines of your own home or with permission from the homeowner. Renting a home would require permission from the homeowner to possess, grow, smoke, vape, or consume cannabis on their property. The law does NOT allow any smoking of cannabis outside of your home. This means that it is strictly prohibited to smoke cannabis in public spaces, such as: on streets, sidewalks, parking lots, alleys, restaurants, bars, on school grounds, in motor vehicles, on public housing property, section 8 housing, parks, beaches, open garages, front porches, outdoor stairwells, on boats, motorcycles, or near anyone under the age of 21.

Additionally, possessing any amount of cannabis on federal land and national parks within Illinois is illegal.

Can I Drive With Cannabis Or Bring Cannabis On Public Transportation?

Transporting cannabis in a vehicle is also regulated through a number of laws. The basic answer is yes, an individual 21 years of age or older can transport cannabis in his/her vehicle within the state of Illinois; however, cannabis must be secured in the sealed child proof container and not accessible to the driver while the vehicle is operating. Traveling across state lines is federally prohibited.

Smoking, vaping, and consuming cannabis on public transportation is strictly prohibited, as public transportation is a public space. This includes all public buses, trains, airplanes, and subways.

Can I Get A Dui If I Drive After Consuming Cannabis?

Yes (sort of)! Just like driving under the influence of alcohol, driving a motor vehicle under the influence of cannabis is also illegal. Such a crime is classified as a Class A misdemeanor that is punishable by up to $2500.00 in fines and up to a year in custody. In the past, any trace amount of cannabis subjected a driver to arrest and prosecution.

But under new Illinois laws, there now is a nanogram “limit” (5 nanograms or more) for what amount of Tetrahydrocannabinol concentration of delta-9-tetrahydrocannabinol [THC 9] is “allowed” before there is a legal presumption that the driver is impaired. This works just like the .08 alcohol limit that has been in place for alcohol DUIs for many years. It doesn’t really mean that you can drive around all day long with 4 nanograms of THC 9 or .07 of alcohol in your system. It just means that if you register higher than that in a DUI blood test, you’re in big trouble. If you’re lower, it doesn’t mean you’re all good. It just means that there is no “presumption” of impairment, even though you still could be found guilty under certain circumstances.

Just like an alcohol DUI, a DUI for cannabis can also have prolonged consequences of your driving privileges. In some cases, your license may be suspended for a period of time, or even revoked.

Speak To An Experienced Criminal Attorney

Laws related to the consumption, purchase, cultivation, sale and use of cannabis can be complicated in Illinois. Our attorneys are knowledgeable about all such cases, whether charged as a petty offense, a misdemeanor or a felony. So, if you have been arrested or charged with a cannabis related offense, whether it’s traffic related or purely criminal in nature, call Mitchell S. Sexner & Associates LLC at (312) 644-0444 and speak to a member of our experienced legal team today.

Written by Mitchell S. Sexner Last Updated : July 13, 2023