According to the regulations pertaining to the Hotel Operators' Occupation Tax, public renting of hotel rooms, "is subject to tax, even if the person paying for the room may be a church, charity, or school or some other kind of nonprofit organization, and even if the person paying for the room may be a governmental agency or instrumentality (Federal, state, or local, or even a foreign government)."
For more information, visit 86 Ill. Adm. Code 480.101.