65 ILCS 5/11-20-14
Notwithstanding any other prohibition to the contrary, a municipality with a population of 1,000,000 or more may, by ordinance, authorize the presence of companion dogs in outdoor areas of restaurants where food is served, if the ordinance provides for adequate controls to ensure compliance with the Illinois Food, Drug, and Cosmetic Act, the Food Handling Regulation Enforcement Act, the Sanitary Food Preparation Act, and any other applicable statutes and ordinances. An ordinance enacted under this Section shall provide that: (i) no companion dog shall be present in the interior of any restaurant or in any area where food is prepared; and (ii) the restaurant shall have the right to refuse to serve the owner of a companion dog if the owner fails to exercise reasonable control over the companion dog or the companion dog is otherwise behaving in a manner that compromises or threatens to compromise the health or safety of any person present in the restaurant, including, but not limited to, violations and potential violations of any applicable health code or other statute or ordinance. An ordinance enacted under this Section may also provide for a permitting process to authorize individual restaurants to permit dogs as provided in this Section and to charge applicants and authorized restaurants a reasonable permit fee as the ordinance may establish.
For the purposes of this Section, "companion dog" means a dog other than a service dog assisting a person with a disability .
65 ILCS 5/11-20-14