A plaintiff is the person, business, or government entity that starts a civil lawsuit by filing a complaint. Examples of a plaintiff include a driver suing after a crash, a homeowner suing a contractor who took the money and disappeared, a fired employee suing for discrimination, a drug company suing a competitor for patent infringement, a state attorney general suing a business for consumer fraud, and a single consumer suing on behalf of thousands in a class action. The thread connecting all of them is simple: each one went to court claiming someone else caused them a specific, legally recognized harm.
Plaintiffs Exist in Civil Cases, Not Criminal Ones
Before the examples, one boundary worth drawing. In a criminal case, the government brings charges against a defendant on behalf of the public, run by a district attorney or federal prosecutor. A private citizen cannot file criminal charges on their own. The role of “plaintiff” belongs to civil court, where a private person, business, or organization files the lawsuit directly, controls the case, hires the lawyer, and decides whether to settle or go to trial. The goal is almost always money or a court order, not jail time. Every example below is a civil plaintiff.
The Injured Driver: A Personal Injury Plaintiff
Personal injury cases produce the most familiar plaintiff. Picture a driver struck by someone running a red light. They spend $15,000 on emergency surgery and months in rehabilitation. As the plaintiff, they must prove the other driver was negligent and that the negligence caused their injuries. The damages they request should cover the full financial impact: hospital bills, physical therapy, lost income during recovery, and compensation for ongoing pain. This is where the phrase “being made whole” comes from. The court tries to put the plaintiff back in the financial position they occupied before the crash.
Other personal injury plaintiffs include a customer who slips on an unmarked wet floor and a patient harmed by a surgical error. Medical malpractice plaintiffs face extra hurdles: they must typically show that a healthcare provider failed to meet the accepted standard of care and that the failure directly caused harm, and many states require a certificate of merit from another medical professional before the case can proceed.
Most personal injury plaintiffs hire attorneys on contingency, meaning the lawyer takes a percentage of the recovery, typically between 20% and 50%, with 33% common for cases that settle before trial.
The Stiffed Homeowner: A Breach of Contract Plaintiff
When someone breaks a deal, the other side becomes a potential plaintiff. A homeowner who pays a contractor $10,000 to renovate a kitchen and gets nothing in return has a straightforward breach of contract claim. A software vendor whose client refuses to pay a $50,000 invoice after the work is delivered has the same.
Contract plaintiffs typically seek one of two remedies. The first is money damages covering the financial loss caused by the breach. The second, used far less often, is specific performance, where the court orders the breaching party to actually do what they promised. Courts reserve specific performance for situations where money alone cannot fix the problem, such as the sale of a unique piece of real estate.1Legal Information Institute. Specific Performance
One thing contract plaintiffs sometimes miss: the duty to mitigate. Once a breach occurs, the injured party cannot sit back and let losses pile up. If a tenant breaks a lease, the landlord needs to make a genuine effort to find a new renter. A landlord who does nothing for six months and then sues for six months of lost rent will likely see the award reduced.
The Fired Employee: A Workplace Plaintiff
Employees and job applicants become plaintiffs when workplace rights are violated. Two scenarios come up again and again.
A wrongful termination plaintiff argues that their firing violated either an employment contract or public policy. Most employment in the United States is “at-will,” meaning either side can end it without a specific reason. But an employer still cannot fire someone for reporting safety violations, refusing to participate in illegal activity, or exercising a legal right like filing a workers’ compensation claim.2USAGov. Wrongful Termination
A discrimination plaintiff often sues under Title VII of the Civil Rights Act of 1964, which prohibits employment decisions based on race, color, religion, sex, or national origin and applies to employers with fifteen or more employees.3U.S. Equal Employment Opportunity Commission. Title VII of the Civil Rights Act of 1964 A job applicant denied a position because of their race can file a charge with the EEOC and ultimately bring a lawsuit as plaintiff.
The payoff can be substantial. Remedies include back pay, reinstatement, and compensatory damages. A plaintiff earning $60,000 a year who was unlawfully fired, in a case that takes two years to resolve, could see back pay alone exceed $120,000. The court may also order the employer to place the plaintiff back in the same role or a comparable one.4U.S. Equal Employment Opportunity Commission. Remedies for Employment Discrimination
The Patent Holder: A Corporate Plaintiff
Plaintiffs are not always individuals. Corporations file lawsuits constantly, and patent infringement is one of the most common corporate plaintiff actions. Under federal law, anyone who makes, uses, or sells a patented invention without authorization infringes the patent.5Office of the Law Revision Counsel. 35 USC 271 – Infringement of Patent A pharmaceutical company that discovers a competitor selling a generic version of its patented drug can sue as plaintiff for an injunction to stop production and for damages covering lost profits. These cases often involve hundreds of millions of dollars and years of litigation.
The State Attorney General: A Government Plaintiff
Federal, state, and local governments regularly appear as plaintiffs. A city might sue a property owner for unpaid taxes. A state attorney general might file suit against a company for consumer fraud. Federal agencies bring civil enforcement actions against businesses that violate regulations. Government plaintiffs carry the same burden of proof as any other civil plaintiff, but they typically have far deeper resources to pursue the case.
The Lead Consumer: A Class Action Representative Plaintiff
When many people suffer the same harm from the same defendant, one or a few individuals can sue as “representative plaintiffs” on behalf of the entire group. Federal Rule of Civil Procedure 23 sets four requirements for class certification: the class must be too numerous for everyone to join individually, there must be legal or factual questions common to the group, the representative plaintiff’s claims must be typical of the class, and the representative must adequately protect the class’s interests.6Legal Information Institute. Federal Rule of Civil Procedure 23 – Class Actions
A defective product that injures thousands of consumers, or a data breach exposing millions of accounts, is the kind of situation that produces a class action. The lead plaintiff drives the litigation while the rest of the class benefits from any resulting settlement or judgment.
What Every Plaintiff Has in Common
Different as these examples look, the people filing them must clear the same basic hurdles.
Standing
Not just anyone can file a lawsuit over any grievance. Courts require “standing,” meaning the plaintiff must show a real, personal injury rather than a hypothetical or abstract one. The Supreme Court has held that the injury must be both “concrete” and “particularized,” meaning it actually happened to the person filing the case and affected them individually.7Congress.gov. ArtIII.S2.C1.6.4.2 Concrete Injury Being generally upset about a company’s behavior is not enough.
Real Party in Interest
Federal Rule of Civil Procedure 17 requires that a lawsuit be brought in the name of the “real party in interest,” meaning the person who actually holds the legal right at stake.8Legal Information Institute. Federal Rule of Civil Procedure 17 Executors, trustees, and guardians can sue on behalf of the people they represent, but a random third party with no legal relationship to the claim cannot step in as plaintiff.
Burden of Proof
Once the case is underway, the plaintiff carries the burden of proof. In most civil cases, that standard is “preponderance of the evidence,” meaning the plaintiff must show that their version of events is more likely true than not. If the evidence is perfectly balanced, the plaintiff loses. This is a much lower bar than the “beyond a reasonable doubt” standard used in criminal trials, which is one reason people acquitted of criminal charges sometimes still lose a civil lawsuit over the same conduct.
A Properly Filed Complaint
The lawsuit officially begins when the plaintiff files a complaint with the court. Under Federal Rule of Civil Procedure 8, the complaint needs three things: a statement explaining why the court has jurisdiction, a plain description of what happened and why it entitles the plaintiff to relief, and a demand for the specific remedy sought.9Office of the Law Revision Counsel. 28 USC App Fed R Civ P Rule 8 – General Rules of Pleading Filing a civil complaint in federal court costs $350.10Office of the Law Revision Counsel. 28 US Code 1914 – District Court Filing and Miscellaneous Fees State court filing fees vary by jurisdiction.
An injured driver, a shortchanged homeowner, a wrongfully fired employee, a drugmaker protecting a patent, a state attorney general, and a lead consumer in a class action look very different from the outside. In court, they all occupy the same chair.