Illinois Divorce Laws (2026): Grounds, Residency, and Process

Illinois is a no-fault-only state: you divorce by proving irreconcilable differences causing an irretrievable breakdown of the marriage. At least one spouse must be an Illinois resident when the petition is filed, and the 90 days of residence can be satisfied either before filing or by the time the court makes its finding on the grounds. No separation period is required.

Grounds for divorce in Illinois

Illinois has been a pure no-fault state since January 1, 2016, when legislation eliminated all fault-based grounds for divorce. Before that reform, spouses could cite adultery, cruelty, abandonment, and other misconduct. Today, the only statutory ground is irreconcilable differences that have caused an irretrievable breakdown of the marriage under 750 ILCS 5/401.

The statute does not require either spouse to assign blame or prove wrongdoing. Either spouse can file unilaterally; the other spouse's agreement is not required to obtain the divorce. Illinois courts do not investigate or adjudicate whether the breakdown was one spouse's "fault."

Because fault was abolished entirely, any history of misconduct during the marriage is generally not considered when dividing property or awarding maintenance in Illinois. There are narrow exceptions, such as dissipation of marital assets, but the divorce itself rests solely on the no-fault ground.

Residency requirement

Under 750 ILCS 5/401(a), one of the spouses must have been a resident of Illinois, or stationed in Illinois as a member of the armed services, at the time the action was commenced. That residence or military presence must have been maintained for 90 days next preceding either the commencement of the action or the making of the finding on irreconcilable differences.

The statute states those two reference points in the alternative, so there are two ways to satisfy the 90 days. A spouse who has already lived in Illinois for 90 days meets the requirement at filing. A spouse who has just moved can still file once Illinois residency is established, and the 90 days can finish running before the court makes its finding. The statute does not require the 90 days to be complete before filing, and it does not tie the count to the date the judgment is entered. Residency itself, though not 90 days of it, is required at the moment the case is commenced.

Divorce cases in Illinois are handled by the Circuit Court. The petition is filed in the county where either spouse resides. Illinois has 102 counties, each with its own Circuit Court division; most large counties have a dedicated family law or domestic relations division.

There is no separate county residency requirement beyond the statewide 90-day rule. If both spouses live in different Illinois counties, either county's Circuit Court has jurisdiction to hear the case.

Waiting period and separation

Illinois does not impose a mandatory cooling-off waiting period between filing the divorce petition and receiving the final decree. An uncontested divorce with no disputed issues can, in theory, proceed to judgment as soon as the 90-day residency requirement is satisfied and all required disclosures have been exchanged.

The 6-month separation provision is often misunderstood. It is not a waiting period that spouses must complete before filing. Instead, it is an evidentiary rule: if the spouses have lived separate and apart for a continuous period of not less than 6 months immediately preceding entry of the judgment, the court treats that separation as conclusive, irrebuttable proof that irreconcilable differences exist (750 ILCS 5/401(a-5)). A judge cannot reject the divorce on the grounds that the breakdown is not genuine once that 6 months is met.

There is nothing to waive, because the separation is not a requirement in the first place. Section 401(a-5) runs in one direction only: 6 months apart proves the ground conclusively. Spouses who have not lived apart can still establish irreconcilable differences directly, which is what happens when the parties state in the petition or a joint filing that the marriage has irretrievably broken down. That is why many Illinois divorces are finalized in a matter of weeks once the paperwork is complete, without any separation period at all. The pre-2016 regime that let spouses shorten a separation period by written stipulation was repealed and no longer applies.

How property is divided

Illinois is an equitable distribution state. Under 750 ILCS 5/503, a court divides only marital property, defined as property acquired by either spouse during the marriage (with limited exceptions). Equitable distribution means the division must be fair under the circumstances, but it does not mean equal: the court considers factors such as the length of the marriage, each spouse's economic circumstances, contributions to the marital estate, and any agreements the parties reached.

Separate property, which includes assets owned before the marriage, gifts and inheritances received by one spouse individually, and property excluded by a valid prenuptial agreement, is not subject to division. The spouse who owns separate property keeps it.

Marital debt is also divided equitably. The court looks at who incurred the debt, what it was used for, and each spouse's ability to repay it.

Alimony, custody, and child support

When a marriage involves financial dependence or children, the dissolution proceeding addresses all related matters. Illinois calls spousal support "maintenance" rather than alimony. Courts consider the income and needs of each spouse, the length of the marriage, and whether a spouse gave up career opportunities for the family. For guidance on Illinois-specific maintenance rules, see the Illinois alimony laws page.

Custody in Illinois is formally called "allocation of parental responsibilities" under the Illinois Marriage and Dissolution of Marriage Act as amended in 2016. Courts allocate decision-making authority over education, health, religion, and extracurricular activities, and set a parenting time schedule. For details on how Illinois courts make these decisions, see Illinois child custody laws.

Child support follows an income shares model in Illinois. Both parents' incomes are combined to determine the presumptive support obligation, which is then allocated proportionally. You can find an overview of calculations and guidelines on the Illinois child support laws page. Estimate your payment with our Illinois child support calculator.

How to file for divorce in Illinois

The process begins with confirming that you or your spouse is an Illinois resident, since the statute requires residency at the time the case is commenced, and then working out whether the 90 days will already be complete at filing or will finish before the court makes its finding. You file the Petition for Dissolution of Marriage in the Circuit Court of the county where you or your spouse lives. The filing fee varies by county; check with the clerk's office in your county for the current amount.

After filing, you must formally serve the petition on your spouse according to Illinois rules of civil procedure. If your spouse agrees to participate, they can sign an Entry of Appearance form to waive formal service.

Both parties are required to exchange financial disclosures. Illinois requires a Financial Affidavit if either party seeks maintenance or if children are involved. This document lists income, expenses, assets, and debts.

If the case is uncontested, the spouses submit a Marital Settlement Agreement covering property, maintenance, and (if applicable) a Parenting Plan. The court reviews the agreement, may ask brief questions at a prove-up hearing, and enters the Judgment for Dissolution of Marriage. If the case is contested, it proceeds through discovery, possible mediation, and ultimately a trial before a judge.

Once the judge signs the Judgment for Dissolution, the divorce is final. Illinois does not impose a nisi period or any post-judgment waiting time before remarriage is permitted.

This article is general legal information, not legal advice. Divorce law varies by state and depends on the specific facts of your marriage. For advice about your situation, consult a licensed family-law attorney in Illinois.

For more on divorce across all states, see the Divorce Laws by State hub. Related Illinois family law topics: Illinois alimony laws, Illinois child custody laws, and Illinois child support laws.

More Illinois Laws

• Illinois Alimony Laws
• Illinois Child Custody Laws
• Illinois Child Support Laws
• Illinois Common Law Marriage Laws
• Illinois Restraining Order Laws
• Illinois Unclaimed Property