Personal jurisdiction is the authority a court has to make legally enforceable orders related to a person or entity and the property of the person or entity, and usually arises when a person has been sued in a lawsuit. For a court to have personal jurisdiction, the person or entity generally (1) must be a resident of the state in which the court is located; (2) as a nonresident, must have initiated sufficient minimum contacts with the state in which the lawsuit is filed; or (3) must have agreed to be governed by the laws of the state (in a contract or website terms) in which the lawsuit is filed.

In Montana, as in other states, personal jurisdiction refers to a court's power to bring a person or entity into its court process and to make decisions affecting that person or entity's rights. For a Montana court to have personal jurisdiction, typically, the defendant must have a significant connection to the state. This can be established if the defendant is a resident of Montana or if the nonresident defendant has sufficient minimum contacts with the state, such as conducting business, owning property, or committing a tort within Montana. Additionally, a person or entity can consent to Montana's jurisdiction through a contractual agreement or by accepting the terms of service on a website that stipulates Montana law will govern disputes. Montana's long-arm statute allows the state's courts to exercise personal jurisdiction to the fullest extent permitted by the Due Process Clause of the U.S. Constitution, meaning the exercise of jurisdiction must also be fair and reasonable.