The governor said the law removes a significant barrier to employment for those whose credit history has been hurt by a very tough recession.
Employers can still investigate applicants' backgrounds, but can't check their credit histories.
"Unfortunately, some employers are using credit score of an individual person to decide whether someone gets hired, or someone gets retained on the job, or someone gets promoted on that job. And I don't think that's fair, and I think members of the General Assembly feel the same way," said Gov. Quinn.
Banks, insurance companies and other firms that deal with confidential financial information are exempt from the new law.