In Illinois, zoning regulations are established by:

The Illinois state government does not itself establish zoning regulations for individual communities; rather, it enables local governments to do so by passing enabling legislation that grants them zoning authority. The state sets the framework and outer limits of zoning power but does not write or administer local zoning ordinances.

The federal government has no direct zoning authority because land-use regulation is a state police power reserved under the Tenth Amendment to the U.S. Constitution. Federal influence on land use occurs indirectly through funding conditions, environmental regulations, and fair housing laws, but the federal government does not establish local zoning codes.

Private developers have no governmental authority to establish zoning regulations, which are a sovereign governmental function requiring legislative enactment. Developers may influence zoning through lobbying, rezoning petitions, or planned unit development agreements, but the actual regulatory authority rests exclusively with government bodies.