A party is a person or group of persons that compose a single entity which can be identified as one for the purposes of the law.

Courts use various terms to identify the role of a particular party in civil litigation, usually identifying the party that brings a lawsuit as the plaintiff, or, in older American cases, the party of the first part; and the party against whom the case was brought as the defendant, or, in older American cases, the party of the second part.

See also

• Ex parte proceeding
• Inter partes proceeding
• Erga omnes