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 Idaho, as in other states, the conflict of laws refers to a set of legal principles used to determine which jurisdiction's laws are applicable in a case involving parties or circumstances with connections to more than one state or jurisdiction. When a legal dispute arises, Idaho courts will look at various factors to decide which state's laws should govern the case. These factors can include the location where a contract was signed or where an injury occurred, the residency or place of business of the parties involved, and the nature of the transaction or event that gave rise to the lawsuit. If the parties have a valid contract that includes a choice of law provision, Idaho courts will generally honor that agreement, unless it contradicts a fundamental policy of the state. In the absence of such an agreement, Idaho courts will apply conflict of laws principles to ensure that the law applied is that of the state with the most significant relationship to the dispute. When federal law is involved, Idaho courts may also have to consider whether federal statutes or constitutional principles preempt state law.