Is Adultery Illegal in California? 2025 Divorce Laws on Adultery Explained

Quick Answer: No, adultery is not illegal in California. The no-fault divorce regime of the state provides that infidelity has nearly zero influence on divorce proceedings—except when infidelity involves financial misbehavior that squanders marital assets.

What Constitutes “Adultery” Under California Law?

California law does not define “adultery” in any criminal code statute because the state decriminalized it decades ago. Typically, adultery is when a married individual has sex with someone other than their spouse. Because California has a no-fault divorce system, the legal definition is less important than you might assume.

Unlike a few other states that get mired in technical terminology, California just calls it like it sees it: no matter if you use the terms adultery, infidelity, or cheating, none of these terms affect how your divorce case will be processed in court.

Is Adultery a Crime in California in 2025?

Not at all. California does not criminalize adultery, which makes it radically different from other states. Although 16 states in America still have laws that criminalize adultery, California eliminated those antiquated statutes decades ago.

States Where Adultery Remains Criminal (2025):

The contrast is striking. In Michigan, Oklahoma, and Wisconsin, for example, adultery is a felony punishable by as much as five years in prison and thousands of dollars in fines. Maryland makes it a crime, but only carries a $10 fine. California, on the other hand, addresses adultery as a family secret, not a criminal offense.

No-Fault Divorce: Why Courts Don’t Punish Infidelity

California pioneered no-fault divorce with the signing of the Family Law Act of 1969 by Governor Ronald Reagan, which became effective on January 1, 1970. This new legislation replaced the old fault system in which couples had to establish wrongdoing—often in situations involving claimed adultery documented by private detectives—to a new requirement: “irreconcilable differences.”

Judges, under California’s no-fault system, can’t penalize an adulterous spouse by granting the faithful spouse more assets or greater alimony. The law emphasizes pragmatic factors, including each spouse’s financial needs and earning potential, over moral assumptions about who caused the breakdown of the marriage.

This approach removes the “blame game” that previously made divorces uglier and more costly. According to one law professor, the old system based on fault was “rife with hypocrisy and lurid accusations” that tended to involve perjury to secure a divorce.

How Adultery Can Indirectly Affect Your Divorce

While adultery alone won’t affect divorce cases, it does have financial implications in some situations:

Property & Debt Allocation (Community Property Rules)

California requires a 50/50 equal split of all community property that is earned during marriage. There is a very large exception, though: dissipation of marital assets.

If your spouse used a lot of marital money on their affair—hotel rooms, fine dining out, gifts, trips, or even rent on an apartment for their paramour, this is dissipation of assets. The court can ask the cheating spouse to pay back the marital estate for these expenses before the remaining assets are divided.

Example: If your spouse spent $25,000 on expenses related to the affair, you might be awarded $12,500 more than the normal 50/50 share to make up for this misappropriation of marital funds.

Spousal Support (Alimony)

California Family Code Section 4320 states that there are 14 factors that judges are required to consider in making spousal support awards. Adultery does not appear on this list. The law emphasizes pragmatic considerations such as:

• Each spouse’s earning ability and level of living during marriage
• Duration of marriage
• Age and health of both spouses
• Ability to pay spouse
• Need for spousal support

But even though adultery per se does not affect alimony, the cheating spouse’s subsequent cohabitation can have an indirect impact. According to Family Code Section 4323, there’s a “rebuttable presumption” that cohabitation decreases the supported spouse’s need for financial support.

Child Custody & Visitation

California maintains the “best interest of the child” when determining custody. Adultery does not impact custody because an affair doesn’t render a person an unfit parent.

The only exception is when the affair actually hurts the children, like:

• Exposing children to sexual misconduct
• Leaving children home alone to pursue the affair
• Moving in with an affair partner who is physically abusing the children
• Rendering the home an unhealthy place to live

Securing Evidence: When & Why It Still Exists

Even though California is a no-fault jurisdiction, evidence of expense due to affairs can be required for dissolution actions. Effective evidence are:

• Hotel bill receipts on credit cards, restaurant bills, jewelry acquisitions
• Cash withdrawal or bank transfer statements
• Travel receipts to trips with the affair partner
• Excessive phone calls’ records
• Social media posts or images

Important note: You’re not gathering this evidence to “prove” adultery for the divorce itself, but to demonstrate financial misconduct that wastes marital assets.

Financial Misconduct & Reimbursement Actions

Dissipation of assets requires proving that marital funds were spent on affair-related expenses during the breakdown of the marriage. Common examples include:

• Hotel and vacation expenses: Romantic getaways with the affair partner
• Gifts and jewelry: Expensive presents for the lover
• Rent: Subsidizing the affair partner’s rent
• Dinner bills: Expensive meals and dates
• Car costs: Car loan or insurance for the affair partner

Reimbursement is possible by adjusting the property division or by having the unfaithful spouse return these funds as their share of the property.

Comparing California to Fault-Based States

California’s approach differs dramatically from states that still consider fault in divorce proceedings:

Key California Family Code Sections to Know

• Family Code § 2550: Mandates equal distribution of community property
• Family Code § 4320: Enumerates factors for spousal support determinations
• Family Code § 4323: Establishes presumption that cohabitation mitigates support obligation
• Family Code § 2310: Specifies grounds for divorce (irreconcilable differences or incurable insanity)

Conclusion: Emphasis on Facts, Not Blame

California’s no-fault divorce system is a reflection of an economic reality: marriages fail for various reasons, and the legal system is more effective when it emphasizes equitable financial resolutions over moral condemnation. Although finding out about a spouse’s adultery is emotionally shattering, the law protects through dissipation claims when affairs financially injure the marriage.

Learning these facts can help you make more informed choices during a stressful period. Instead of punishing cheaters, California law promotes building stable, independent lives for both spouses and their children.

Ready to begin your California divorce? Admitting adultery or any other marital problem, Instantonlinedivorce.com can guide you through California’s no-fault system quickly and at an affordable price so that you can proceed with confidence and clarity.