Grounds for Divorce in Illinois

In Illinois, divorce laws have evolved significantly over time, moving from fault-based grounds to a no-fault system. This shift has simplified the divorce process, but understanding what it means is crucial.

What are the grounds for divorce in Illinois?

In the past, Illinois, like many states, followed a fault-based divorce system. This meant that one spouse needed to prove the other was at fault due to reasons such as desertion, abandonment, extreme cruelty, or incurable mental illness. The accusing spouse had to provide evidence, making the process potentially contentious and time-consuming.

Illinois law has since evolved. As of January 1, 2016, Illinois adopted a purely no-fault system, making “irreconcilable differences” the sole legal ground for divorce.

A no-fault divorce means that neither spouse needs to prove the other did something wrong to cause the marriage's breakdown. Instead, the couple simply needs to agree that irreconcilable differences have led to the irretrievable breakdown of their marriage. This change has made the process less adversarial and more focused on resolution.

What to do before filing for divorce in Illinois

Before filing for divorce in Illinois, there are several key requirements:

  • Meet the residency requirement: At least one spouse must have lived in Illinois for a minimum of 90 days before filing.
  • Meet the separation requirement: Illinois requires spouses to be separated for at least six months prior to filing for divorce. This does not mean you or your spouse need to move out. You simply need to separate as husband and wife. Simply moving to a different bedroom and living together as roommates instead of spouses is enough for this requirement.

Unlike some states, Illinois does not impose a waiting period for uncontested divorces. If your spouse doesn't want a divorce, this will delay the process, but it won't stop the divorce from proceeding.

Alternatives to divorce in Illinois

While divorce may seem like the only option when a marriage breaks down, Illinois state law provides alternatives: legal separation, annulment, and Joint Simplified Dissolution.

Legal separation

This allows couples to live separately without formally ending their marriage. Legal separation can determine child custody, visitation, child support, and alimony, just like a divorce decree.

Legal separation and divorce share many similarities, but they also have distinct differences. Both involve a legal process that establishes the rights and responsibilities of each spouse while they live apart. And, both processes can determine aspects of the break-up such as child custody, child support, property distribution, and alimony in a formal separation agreement.

There are specific circumstances where legal separation may be preferable to divorce. Here are some reasons why:

  • Preservation of marital status: Some couples may choose legal separation to maintain their marital status for religious reasons, or because they hold out hope for reconciliation.
  • Financial considerations: Legal separation can be beneficial for financial reasons. It allows the couple to continue sharing benefits such as health insurance, tax benefits, or military benefits that they could lose in a divorce.
  • Personal reasons: A couple may choose legal separation over divorce due to personal reasons or beliefs. Being legally separated can provide a sense of distance and independence while still maintaining the legal connection of marriage.

Divorce legally ends a marriage, whereas legal separation does not. In a legal separation, the couple is still legally married despite the fact that they live apart. Neither person can remarry. Once divorced, however, both parties are free to get married again.

Read: Should We Legally Separate?


Also known as a declaration of invalidity, annulments are rare and apply only in specific circumstances such as fraud, bigamy, inability to consent, and underage marriage. 

An annulment is an alternative to divorce when it can be proven that the marriage was invalid from the start. In other words, the law views an annulled marriage as if it never occurred. 

Here are a few instances where opting for an annulment may be more suitable than filing for divorce:

  • Fraud or misrepresentation: If one spouse lied or withheld essential information that would have impacted the other's decision to marry, an annulment may be appropriate. For example, if a spouse was already married to someone else (bigamy) or lied about their ability or intention to have children, the deceived spouse might have grounds for an annulment.
  • Underage marriage: If one or both parties were below the legal age of consent at the time of the marriage and parental or court consent was not obtained, an annulment can be granted. For instance, if a 16-year-old marries without obtaining proper consent, the marriage can be annulled.
  • Inability to consent: If a spouse was unable to understand the implications of marriage due to mental incapacity or the effects of drugs or alcohol, or if they were forced or threatened into the marriage, they can seek an annulment.
  • Incestuous marriage: A marriage between close relatives is considered incestuous and can be annulled.

Joint Simplified Dissolution

In Illinois, Joint Simplified Dissolution is a quicker and simpler way to divorce for couples who meet certain criteria. Among other things, the criteria include being married for less than eight years, having no children, and having limited marital assets and debts. Importantly, both spouses must agree that divorce is the right step and must file all paperwork together.

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Divorce Content Specialist & Lawyer
Divorce Strategy, Divorce Process, Legal Insights

Bryan is a non-practicing lawyer, HR consultant, and legal content writer. With nearly 20 years of experience in the legal field, he has a deep understanding of family and employment laws. His goal is to provide readers with clear and accessible information about the law, and to help people succeed by providing them with the knowledge and tools they need to navigate the legal landscape. Bryan lives in Orlando, Florida.