Well, not exactly.

Court supervision is a sentence allows under Illinois law where a defendant can plead guilty and agree to a set of terms whereby if the defendant successfully completes the terms, the court will not enter a conviction. Part of receiving court supervision is entering a guilty plea.

Why is that? Because if a defendant on court supervision violates the terms of court supervision, the court can resentence them on the charge they pled guilty to without having a trial on the original charge. So suppose Billy commits a theft, is caught and pleads guilty to theft (a Class A misdemeanor in Illinois) and in exchange for a guilty plea is placed on court supervision for 24 months. Suppose Billy commits another theft 23.99 months after being placed on supervision. The prosecution can petition the court to revoke Billy's court supervision and resentence him over two years after the first offense without a trial for theft. The prosecution would need to prove by a preponderance of the evidence that Billy violated his supervision (a proceeding to revoke a community based sentence isn't held at the "beyond a reasonable doubt " standard). If the prosecution meets thier burden, Billy can now get anything ranging from court supervision (again) for up to two years, probation for up to two years and 364 days in jail and a $2500 fine, or anything in between. So suppose Billy is resentenced to probation for 24 months based on the supervision violation, and 23.99 months latter, violates probation (about 4 years after the first theft). Billy is right back where he started when he pled guilty 4 years ago, and because he pled guilty, there was and never will be a trial.

So, yes, OP can plead guilty and not be convicted. Happens every day in courtrooms all across Illinois.