In law, a legal person is any person or 'thing' (less ambiguously, any legal entity) that can do the things an everyday person can usually do in law – such as enter into contracts, sue and be sued, own property, and so on. The reason for the term "legal person" is that some legal persons are not people: companies and corporations are "persons" legally speaking (they can legally do most of the things an ordinary person can do), but they are clearly not people in the ordinary sense.
There are therefore two kinds of legal entities: human and non-human. In law, a human person is called a natural person (sometimes also a physical person), and a non-human person is called a juridical person (sometimes also a juridic, juristic, artificial, legal, or fictitious person, Latin: persona ficta).
While natural persons acquire legal personality "naturally", simply by being born (or before that, in some jurisdictions), juridical persons must have legal personality conferred on them by some "unnatural", legal process, and it is for this reason that they are sometimes called "artificial" persons. In the most common case (incorporating a business), legal personality is usually acquired by registration with a government agency set up for the purpose. In other cases it may be by primary legislation: an example is the Charity Commission in the UK. The United Nations Sustainable Development Goal 16 advocates for the provision of legal identity for all, including birth registration by 2030 as part of the 2030 Agenda.
As legal personality is a prerequisite to legal capacity (the ability of any legal person to amend (enter into, transfer, etc.) rights and obligations), it is a prerequisite for an international organization to be able to sign international treaties in its own name.
In part based on the principle that legal persons are simply organizations of natural persons, and in part based on the history of statutory interpretation of the word "perso
In part based on the principle that legal persons are simply organizations of natural persons, and in part based on the history of statutory interpretation of the word "person", the US Supreme Court has repeatedly held that certain constitutional rights protect legal persons (such as corporations and other organizations). Santa Clara County v. Southern Pacific Railroad is sometimes cited for this finding because the court reporter's comments included a statement the Chief Justice made before oral arguments began, telling the attorneys during pre-trial that "the court does not wish to hear argument on the question whether the provision in the Fourteenth Amendment to the Constitution, which forbids a State to deny any person within its jurisdiction the equal protection of the laws, applies to these corporations. We are all of the opinion that it does."
Later opinions interpreted these pre-argument comments as part of the legal decision. As a result, because of the  As a result, because of the First Amendment, Congress may not make a law restricting the free speech of a corporation or a political action group or dictating the coverage of a local newspaper, and because of the Due Process Clause, a state government may not take the property of a corporation without using due process of law and providing just compensation. These protections apply to all legal entities, not just corporations.
A prominent component of relevant case law is the Supreme Court decision Citizens United v. Federal Election Commission, which ruled unconstitutional certain restrictions on corporate campaign spending during elections.
In Act II, Scene 1 of Gilbert and Sullivan's 1889 opera, The Gondoliers, Giuseppe Palmieri (who serves, jointly with his brother Marco, as King of Barataria) requests that he and his brother be also recognized individually so that they might each receive individual portions of food as they have "two independent appetites". He is, however, turned down by the Court (made up of fellow Gondolieri) because the joint rule "... is a legal person, and legal person are solemn things."