In Illinois, you must be at least 21 years old to enter a casino. This age requirement applies to all casinos in the state, regardless of location. It is strictly enforced to comply with state gambling laws and regulations. Minors are not permitted on the gaming floor or allowed to participate in any form of gambling. Casinos may ask for identification to verify age before granting entry to patrons. Remember to always carry a valid ID when visiting a casino in Illinois.