In addition to legalizing marijuana, the 610-page bill offers relief to the roughly 770,000 residents of the state with marijuana-related offenses on their criminal records, according to the Marijuana Policy Project.
The bill also includes a "social equity program," which makes it easier for those with marijuana convictions to get business licenses.
Pritzker is fulfilling a promise he made on the campaign trail and is making Illinois the 11th U.S. state to legalize recreational marijuana.
So far 18 states have decriminalized marijuana, the MPP says, and in all 34 states allow patients with health complaints to use medical marijuana.
And Illinois is the latest state to offer clemency for marijuana convictions.