What Is Parens Patriae? Definition and Examples

What Is Parens Patriae? Definition and Examples

Parens patriae is a legal term referring to the power of the government to act on behalf of people who are unable to care for themselves. For example, the doctrine of parens patriae empowers a judge to assign or reassign custody of a minor child, regardless of the parents' wishes. In practice, parens patriae may be applied as narrowly as representing the interests of a single child and as broadly as protecting the wellbeing of the entire population.

Key Takeaways: Parens Patriae

  • Parens patriae is a Latin term meaning “parent of the fatherland."
  • It is a legal term that refers to government's power to act as the legal guardian for people who are unable to care for themselves.
  • Parens patriae is most commonly applied to cases regarding the custody and care of minor children and disabled adults.
  • However, parens patriae is also applied in lawsuits between the states and in suits dealing with the wellbeing of a state's entire population, e.g. environmental concerns or natural disasters.

Parens Patriae Definition

Parens patriae is a Latin term meaning “parent of the fatherland.” In law, it is the power of the government-through the courts-to intervene on the behalf of individuals or groups of individuals who are unable to represent their own interests. For example, children and disabled adults who lack willing and able caregivers often require the intervention of the courts through the doctrine of parens patriae.

Rooted in 16th century English Common Law, parens patriae was considered in feudal times to be the “royal prerogative” of the king, as the father of the country, to act on behalf of the people. During the 17th and 18th centuries, the term became more closely associated with the power of the courts to protect the rights of children and incapacitated adults.

Parens Patriae Doctrine in the United States

In the United States, parens patriae has been expanded by the courts to include the power of the state to act on the behalf of all of its citizens regardless of their age or health.

Precedence for this far broader application of parens patriae was established by the U.S. Supreme Court in the 1900 case of Louisiana v. Texas. In the case, Louisiana sued to prevent Texas from using its public health quarantine regulations to prevent Louisiana merchants from sending goods into Texas. In its landmark decision, the Supreme Court acknowledged that Louisiana had the power to bring the suit as parens patriae representative of all of its citizens rather than any individual person or business.

In the 1972 case of in Hawaii v. Standard Oil Co., the State of Hawaii sued four oil companies seeking to recover damages to its citizens and general economy resulting from price fixing. While the Supreme Court ruled that Hawaii could sue as parens patriae guardian of its people, it could do so only to force the oil companies to end their illegal pricing collusion, not for monetary damages. The citizens, said the court, would have to sue individually for damages.

The Broader Applications of Parens Patriae

In 1914, the U.S. Congress enacted the Clayton Antitrust Act, granting broad powers to the state attorneys general to file parens patriae suits on behalf of their citizens or corporations harmed by violations of the Sherman Antitrust Act.

This broader application of parens patriae was tested in the 1983 case of Pennsylvania v. Mid-Atlantic Toyota Distributors, Inc. In this high-profile case, the Fourth U.S. Circuit Court in Maryland ruled that the attorney generals of six states had legal standing to act as parens patriae plaintiffs in a lawsuit to recover damages for their citizen who had been overcharged in a price-fixing scheme by a group of car dealers. The court reasoned that since the price-fixing scheme had violated federal antitrust laws, state laws, and state constitutions, the states could sue on behalf of their citizens.

Since the states have thus been empowered to act as the trustee of the public, a growing number of parens patriae suits are being filed in cases involving the wellbeing of the general population rather than specific monetary damages. Often involving natural resource disasters, such as oil spills, hazardous waste releases, and the effects of climate change, the prevalence of parens patriae actions is likely to increase in the future.

For example, in 2007, Massachusetts led a group of mostly East Coast states in suing to force the Environmental Protection Agency (EPA) to regulate greenhouse gas emissions they claimed were causing rising sea levels due to global warming. “These rising seas have already begun to swallow Massachusetts' coastal land,” stated the petitioners. In the resulting case of Massachusetts v. EPA, the Supreme Court ruled that the states had legal standing as parens patriae to sue the EPA.

In April 2018, a coalition of 17 states led by California filed a preemptive parens patriae lawsuit against President Donald Trump over his proposal to rollback implementation of tougher national vehicle fuel economy standards established by President Barack Obama. In its petition, California called the EPA's plan to weaken auto emissions rules an unlawful violation of the Clean Air Act. “This is about health, it's about life and death,” former California Governor Jerry Brown said at the time. “I'm going to fight it with everything I can.”


  • “parens patriae.” Nolo's Plain-English Law Dictionary
  • Himes, Jay L… “Two Enforcers Separated by a Common Mission: Public and Private Attorneys General.” The Federal Bar Council (2008).
  • “Massachusetts v. Environmental Protection Agency.” Ballotpedia
  • “Supreme Court: Heat-Trapping Carbon Dioxide is Pollution.” Natural Resources Defense Council, Inc. (2007).
  • Tabuchi, Hiroko and Davenport, Coral. “.”California Sues Trump Administration Over Car Emissions Rules New York Times (2018)