This ordinance came after the U.S. Supreme Court ruled that municipalities do not violate the Eighth Amendment's "cruel and unusual punishment" clause by enforcing bans on people sleeping outside in public places.
The ordinance prohibits people from sleeping or camping on any public sidewalk, street, alley or park.
But village officials said the ban will not affect people who camp outside the Allstate Arena while waiting to get in.
Rosemont said there are exemptions for special events, such as K-pop concerts at Allstate Arena.
Fans sometimes camp outside the venue days in advance, hoping to be among the first ones inside.