When there is more than one state, or more than one jurisdiction (state court, federal court) with a significant relationship to the parties and circumstances involved in a lawsuit or dispute, the question may arise as to which state or jurisdiction’s laws will govern the lawsuit or dispute. The body of law that determines what law governs a dispute is called conflict of laws and consists of legal principles courts use to determine which state or jurisdiction’s law applies—unless the parties to a dispute have agreed (usually in a contract) on what law will apply.

In Wisconsin, as in other states, the issue of which jurisdiction's laws apply to a lawsuit or dispute is governed by the principles of 'conflict of laws' or 'choice of law.' These principles are designed to resolve questions of which state or jurisdiction's substantive law should be applied when there are competing jurisdictions connected to the parties or the circumstances of the case. Wisconsin courts will consider various factors, such as the location where a contract was signed or where an injury occurred, the residency or place of business of the parties involved, and the jurisdiction with the most significant relationship to the dispute. In contractual agreements, parties often include a 'choice of law' clause that specifies which jurisdiction's laws will govern in the event of a dispute. Absent such an agreement, Wisconsin courts will apply conflict of laws principles to determine the applicable law, taking into account the interests and policies of the involved jurisdictions, the need for predictability in legal systems, and the fairness to the parties.