The Illinois Certificate of Dissolution of Marriage, Invalidity or Legal Separation is a document used to legally dissolve a marriage. It can also be used to establish an invalid or legally separated marriage. The document is issued by the State of Illinois and is usually filed with the Illinois Department of Public Health. The Illinois Certificate of Dissolution of Marriage, Invalidity or Legal Separation can be obtained from the County Clerk or the Clerk of the Circuit Court in the county where the marriage occurred. It must be signed by both spouses and filed with the court. There are two types of Illinois Certificate of Dissolution of Marriage, Invalidity or Legal Separation: 1. Certificate of Dissolution of Marriage: This document is used to dissolve a valid marriage. It is used to declare the marriage legally dissolved and end all legal rights and responsibilities associated with the marriage. 2. Certificate of Invalidity or Legal Separation: This document is used to declare a marriage invalid or legally separated. It is used to declare a marriage voidable or void, or to legally separate the parties without dissolving the marriage.