To obtain a legal name change in Illinois, an applicant must submit a petition to the court and the petition must be verified “by the affidavit of some credible person.” The applicant must publish notice of the petition in the newspaper for three consecutive weeks, starting at least six weeks before the hearing. The publication requirement is waived if the name change is for witness protection purposes. Individuals who are not currently incarcerated but have a felony conviction within the last ten years are not permitted to change their name. Registered sex offenders are not permitted to change their name. (735 Ill. Comp. Stat. Ann. 5/21-101 to 5/21-105).
For instructions on legal name changes for minors under 18 in Illinois, see NCTE's Name Changes for Minors in Illinois resource.