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 New York, personal jurisdiction refers to the power of New York courts to bring a person or entity into a legal action and to make decisions that are legally binding upon them. The New York Civil Practice Law and Rules (CPLR) govern the conditions under which the state's courts have personal jurisdiction. Generally, a court in New York may assert personal jurisdiction over a defendant if the defendant is a resident of New York or if the defendant, as a nonresident, has established sufficient minimum contacts with the state. These contacts must be such that the exercise of jurisdiction would be fair and reasonable. This could include conducting business in the state, owning property in the state, or committing a tortious act within the state. Additionally, a nonresident may consent to New York's jurisdiction by agreeing to it in a contract, including website terms of service, or by appearing in court without contesting jurisdiction. New York also has a 'long-arm statute' that allows courts to reach defendants outside of the state under certain circumstances, such as when they transact business in New York or contract anywhere to supply goods or services in the state.