Plaintiff: the party who initiates a civil action

Role and procedure

The plaintiff sets out the facts and legal basis for relief in the initiating document and must serve that document on the opposing party, the defendant. Typical steps after filing include service of process, the defendant's response, discovery of evidence, pretrial motions and potentially trial. The plaintiff generally bears the burden of establishing the claim by the applicable standard of proof (for civil cases this is often the preponderance of the evidence) and seeks remedies such as damages, injunctions or declaratory judgments.

Plaintiffs may be required to pay filing fees or post security in some jurisdictions. They can appear in court personally or through counsel. Where many people share similar claims, one or more plaintiffs may represent the group in a class action. In small-claims or administrative settings the initiating paperwork is simplified and the party who starts the process may be called a claimant or complainant.

Common contexts

• Torts: personal injury, negligence, defamation.
• Contract disputes: breach of contract, warranty issues.
• Property and landlord-tenant matters.
• Consumer protection, employment and civil rights claims.
• Class actions and public interest litigation.

History and terminology

The word "plaintiff" derives from older Anglo‑Norman and French legal language that described a person who makes a complaint in court. Modern legal systems use a variety of labels: "plaintiff" is common in many common-law jurisdictions, but other systems or procedural rules may prefer "claimant," "complainant," or "petitioner" depending on the type of proceeding. The precise meaning can vary by country and by the branch of law involved.

Distinctions and notable points

It is important to distinguish the plaintiff from related roles. The defendant is the party alleged to have caused harm; the prosecutor is the government lawyer in a criminal case; a petitioner often seeks an equitable remedy in nonstandard proceedings. The document that initiates a case may be called a complaint, claim form or lawsuit filing depending on jurisdiction and practice.

Understanding who qualifies as a plaintiff also involves the legal concept of standing: courts require plaintiffs to show a sufficient connection to and harm from the law or action challenged to support their claim. This ensures that courts resolve concrete disputes rather than abstract disagreements.