For more information on visiting casinos in Oklahoma, or for tourist information, call the Oklahoma Tourism Department at (800) 652-6552 or go to: The minimum gambling age is 18 at some casinos and 21 at others.If you are between 18 and 21 and want to legally gamble at a casino, youll have to leave the country.required age to gamble at winstar casino in oklahoma required age to gamble at winstar casino in oklahoma How to choose the best casino. This includes most state lotteries and horse tracks. For many other types of gambling, 18 is the minimum age.