Wisconsin has a "no-fault" divorce law: the only ground for divorce is that the marriage is irretrievably broken. If one party claims that the marriage is irretrievably broken but the other party claims that it is not, the court considers all relevant factors and makes a determination as to whether there are any reasonable prospects of reconciliation. If the court finds that there are no such reasonable prospects, the court can find the marriage irretrievably broken and grant the divorce. If the court finds that there are reasonable prospects of reconciliation, the court shall adjourn the matter for 30 to 60 days and suggest that the parties seek counseling or order the parties to undergo counseling. If at the subsequent hearing either party states that the marriage is irretrievably broken, the court will find that the marriage is irretrievably broken.

If parties need to live separately but neither party believes the marriage is irretrievably broken, there is a separate action for legal separation which the parties may use to establish rights and obligations while legally separated. An action for legal separation may result in a decree for divorce if one of the parties requests a divorce decree, in which case the court after a hearing determines which decree should be granted. If a decree of legal separation is granted, it may later be converted to a divorce decree by stipulation of the parties, or after a year has passed, upon motion of one party.

The state residency requirement for divorce is six months, but there is no state residency requirement for legal separation. The county residency requirement for both actions is 30 days. Someone moving into Wisconsin must wait six months before they can file for divorce, but may file for legal separation after 30 days. However, if a spouse moves into the state with children and files for legal separation after 30 days, the other spouse might be able to challenge the court's jurisdiction over the child custody issue on the basis of the Uniform Child Custody Jurisdiction Act.

Actions for divorce or legal separation are commenced with the filing of a summons and petition and service of the documents on the other party, or by the filing of a joint petition, in which case a summons is unnecessary.

A final hearing on the petition cannot occur until 120 days after service of the petition on the respondent, or 120 days after filing of a joint petition. During the period of time prior to the final hearing, the rights and obligations of the parties may be established by a temporary order, which is usually issued by a family court commissioner. Therefore a motion and affidavit for a temporary order are usually filed and served along with the summons and petition, and a hearing before a family court commissioner is usually held shortly after the action is commenced.

The form of the hearing before the family court commissioner varies from county to county, but is generally less formal than proceedings before a circuit court judge. The family court commissioner may decide, on a temporary basis, such issues as the custody and placement of children, child and spousal support, and the temporary division of property. Although these temporary determinations are not supposed to have "precedental" value at the final hearing, the party which prevails before the family court commissioner may have obtained a significant strategic advantage over the other party. The decision of the family court commissioner may be appealed to the circuit court, or a hearing to revise a temporary order may be brought before the family court commissioner if new evidence or a change in circumstances warrants reconsidering the terms of the temporary order.

If the parties cannot through direct negotiation resolve issues involving the custody and/or placement of children, the court will refer the parties to mediation unless the court finds that requiring mediation will cause undue hardship or would endanger the health or safety of one of the parties. If the parties cannot reach an agreement in mediation, then the parties must prepare for a trial on the issue. The court will appoint an attorney to represent the best interests of the children, and in most counties also order a custody study to be performed by a social worker or other appropriate professional. Often the results of the custody study and the opinions of the attorney for the children will help the parties reach an agreement before trial.

If the parties are able to resolve all issues through negotiation and/or mediation, then a stipulated agreement will be drafted and signed by the parties and the court will hold a short final hearing on the petition and the agreement and (usually) grant the decree requested. If the court finds the agreement grossly unfair to one of the parties or contrary to the best interests of the children, the court may reject the agreement and adjourn the matter. This rarely happens, but may occur if neither party is represented by an attorney and an unacceptable agreement is presented to the court.

If the parties cannot reach a comprehensive agreement, a trial will be held on all or some of the issues and the court will make findings of fact and conclusions of law based upon the evidence presented and according to applicable statutory and case law.