Before you can file for divorce in Illinois, you or your spouse must have resided in Illinois for at least 90 days. If you share children, one of you must have lived in Illinois for at least 180 days.
Several factors determine how long your divorce will take. Typically, uncontested divorce can take place within a few weeks or months; a contested divorce can take a lot longer. The best way to speed up your divorce is to reach agreements with your spouse rather than hashing things out in court.