To file for divorce in Illinois, one spouse must be a resident of the state for at least 90 days prior to filing. Those who are in the military and have been stationed in the state for at least 90 days may also file in Illinois. Furthermore, the divorce will be filed in the county where residency has been established.
The state recognizes both no-fault divorces and fault based divorces. A no-fault based divorce may be filed when the parties have not lived together for two years and the divorce is caused by irreconcilable differences. A divorce may be considered a fault based divorce when one of a number of conditions are met.
Firstly, if a spouse has been willfully absent for one year, this may be grounds for a fault based divorce. Other grounds include being previously married and never divorced, habitual drunkenness or drug use for at least two years, repeated and extreme physical or mental abuse, transmission of a sexually transmitted disease, adultery, impotence and felony conviction.
Although a divorce may be an emotional event, much of the divorce process is governed by state law. Therefore, it may be worthwhile to consult with a family law attorney prior to filing for divorce. An attorney may be able to help a petitioner decide whether a divorce would be classified at as a no-fault or fault based divorce. This may determine whether anyone is eligible for spousal or child support as part of a settlement.
Source: DivorceSupport.com, "Illinois Divorce Laws", September 20, 2014