A private attorney general is an informal term originating in common law jurisdictions for a private attorney who brings a lawsuit claiming it to be in the public interest, for example, benefiting the general public and not just the plaintiff, on behalf of a citizen or group of citizens. The attorney may, at the equitable discretion of the court, be entitled to recover attorney's fees if they prevail. The rationale behind this principle is to provide extra incentive to private attorneys to pursue suits that may be of benefit to society at large. Private attorney general suits are commonly, though not always, brought as class actions in jurisdictions that permit the certification of class action lawsuits.

Origin.

Historically in English common law, a writ of qui tam was a writ through which private individuals who assist a prosecution can receive for themselves all or part of the damages or financial penalties recovered by the government as a result of the prosecution. Its name is an abbreviation of the Latin phrase qui tam pro domino rege quam pro se ipso in hac parte sequitur, meaning " who sues in this matter for the king as well as for himself." While the writ fell into disuse in England and Wales following the Common Informers Act 1951, it remains current in the United States under the False Claims Act, 31 U.S.C. § 3729, which allows a private individual, or "whistleblower" (or relator), with knowledge of past or present fraud committed against the federal government to bring suit on its behalf. This allowance and, in some cases, reliance on private individual litigation to enforce the law has also been referred to as a "bounty" system due to the private citizen's potential financial gain if the suit is successful. There are also qui tam provisions in 18 U.S.C. § 962 regarding arming vessels against friendly nations; 25 U.S.C. § 201 regarding violating Indian protection laws; 46 U.S.C. § 80103 regarding the removal of undersea treasure from the Florida coast to foreign nations; and 35 U.S.C. § 292 regarding false marking. However, in February 2011, the qui tam provision regarding false marking was held to be unconstitutional by a U.S. District Court, and, in September of that year, the enactment of the Leahy–Smith America Invents Act effectively removed qui tam remedies from § 292. Contemporary private attorney general lawsuits are an outgrowth of the rationale underlying the writ of qui tam that enabling private citizens to enforce the law will strengthen enforcement and contribute to the rule of law.