Adultery & Divorce in Illinois: What You Need to Know About Infidelity and Dissolution of Marriage

Before January 1, 2016, Illinois divorce laws recognized fault grounds for divorce, including adultery, alcoholism, mental and physical abuse, and more. However, significant changes to the Illinois Marriage and Dissolution of Marriage Act removed those grounds and made Illinois a pure no-fault divorce state. This means that the legal reason for divorce in Illinois is now solely based on “irreconcilable differences”. It must be shown that these differences are not only irreparable but also that it’s in the best interest of the parties involved to end the marriage.

Even if your spouse’s adultery may have caused the irretrievable breakdown of your marriage, their infidelity isn’t the direct legal grounds for a divorce; rather, it is the breakdown of the marriage itself. It’s crucial for Illinois residents to understand that the monetary elements of a divorce in Illinois—such as child support, alimony (also known as spousal maintenance), and property division—are generally not determined with any regard to marital misconduct like adultery.

How Does Adultery Affect Divorce in Illinois? Understanding the Legal Implications

Many people believe that proof of infidelity will heavily impact their Illinois divorce settlement. However, as a no-fault divorce state, Illinois courts generally operate under the principle that marital misconduct, including adultery, does not directly influence the outcomes of property division, spousal maintenance or alimony awards, or child custody determinations. The focus remains on equitable distribution and the best interests of the child, rather than assigning blame for the marriage’s breakdown.

Adultery and Alimony (Spousal Maintenance) in Illinois

Adultery may be the reason for a marriage’s dissolution, but Illinois courts cannot use it as a direct factor to determine alimony awards (spousal maintenance). The legal framework is designed to ensure decisions are fair and reasonable for both parties, without bias due to marital misconduct. Instead of basing a decision on marital infidelity, judges review specific financial and marital factors when determining spousal support:

• The length of the marriage.
• The age and physical and emotional well-being of each spouse.
• Each spouse’s income, current and future earning capacity, and financial needs.
• The marital property and non-marital property of both spouses.
• Whether the spouse seeking alimony has the time to acquire appropriate education, training, or employment while supporting themselves, or if they must instead care for a child/children with no time for employment.
• Any valid prenuptial or postnuptial agreements.

Adultery and Property Division in Illinois Divorce Cases

Illinois operates under the principle of equitable distribution when dividing marital property. This means assets acquired during the marriage are divided fairly, though not necessarily equally. The court is explicitly barred by law from considering marital misconduct like adultery when deciding how marital property should be divided.

However, there is a significant exception: dissipation of assets. If a spouse used marital funds to further an extramarital affair, such as purchasing lavish gifts, funding vacations, or paying for rent for a lover, these expenditures could be considered dissipation of marital assets. In such cases, the court may require the cheating spouse to reimburse the marital estate for the misused funds. It is crucial to gather clear documentation of such financial misconduct to strengthen a claim for dissipation of assets.

Adultery and Child Custody (Parental Responsibilities) in Illinois

When it comes to child custody – officially termed the “allocation of parental responsibilities” in Illinois – the court’s paramount concern is always the best interests of the child. Generally, adultery itself does not directly impact child custody arrangements or parenting time. The court typically focuses on each parent’s ability to provide a stable and safe environment, their relationship with the child, and their ability to cooperate on parenting matters.

However, there are circumstances where a parent’s infidelity could indirectly affect child custody decisions. For example, if the adulterous relationship exposes the child to harmful, unsafe, or inappropriate situations, or if it significantly distracts the adulterous parent from their parental responsibilities, the court might consider these factors when determining the allocation of parental responsibilities and parenting time. The court prioritizes the child’s welfare, so any elements jeopardizing their safety and well-being will be taken into account.

Recent Updates to Illinois Divorce and Family Law (2025)

While the core principles of no-fault divorce and the limited impact of adultery on financial outcomes remain consistent in Illinois, it’s important to be aware of other recent legislative updates to the Illinois Marriage and Dissolution of Marriage Act. As of June 2025, there have been some changes that may affect your divorce proceedings:

• Spousal Maintenance for Incarcerated Payors: Illinois law no longer automatically pauses spousal maintenance payments if the paying spouse is incarcerated. This change addresses a previous loophole.
• Parental Responsibilities Judgments: Parenting plans, once approved by the court, are now considered final orders, making them immediately enforceable and appealable. However, if the underlying divorce case is dismissed, the parenting plan is voided.
• Parental Relocation Measurement: For determining parental relocation, courts now measure distance based on the shortest surface-road route, rather than straight-line distance. The mileage limits (25 miles for certain counties like Cook, DuPage, Kane, McHenry, and Will, and 50 miles for others) remain the same.
• Confidentiality of Court-Ordered Therapy: Conversations from court-ordered therapy sessions are now governed by HIPAA and the Mental Health and Developmental Disabilities Confidentiality Act, meaning they could be considered by the court in some circumstances.

Navigating Adultery and Divorce with Chicago & Oak Park Family Law [Professional/Team]

Dealing with adultery during a divorce in Illinois can be emotionally taxing, even if its legal impact is generally limited. It’s essential to focus on the practical aspects of your case, ensuring your financial future and the well-being of your children are protected.

The experienced family law attorneys at Conniff & Keleher, LLC are dedicated to helping clients in Chicago, Oak Park, and surrounding regions navigate the complexities of dissolution of marriage or civil union. Our knowledgeable and compassionate team provides comprehensive assistance with child support, spousal maintenance, and property division. We understand the nuances of Illinois divorce law and can guide you through every step of the legal process.

Contact Conniff & Keleher, LLC today to speak with our Chicago and Oak Park family law team and learn more about how we can help you achieve a fair and equitable resolution in your divorce.