In law, a legal person is any person or legal entity that can do the things a human person is usually able to 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 human persons: companies and corporations (i.e., business entities) are persons legally speaking (they can legally do most of the things an ordinary person can do), but they are not, in a literal sense, human beings.

Legal personhood is a prerequisite to legal capacity (the ability of any legal person to amend – i.e. enter into, transfer, etc. – rights and obligations): it is a prerequisite for an international organization being able to sign international treaties in its own name.

The concept of legal personhood for organizations of people is at least as old as Ancient Rome: a variety of collegial institutions enjoyed the benefit under Roman law.

The doctrine has been attributed to Pope Innocent IV, who seems at least to have helped spread the idea of persona ficta as it is called in Latin. In canon law, the doctrine of persona ficta allowed monasteries to have a legal existence that was apart from the monks, simplifying the difficulty in balancing the need for such groups to have infrastructure though the monks took vows of personal poverty.

Another effect of this was that, as a fictional person, a monastery could not be held guilty of delict due to not having a soul, helping to protect the organization from non-contractual obligations to surrounding communities. This effectively moved such liability to persons acting within the organization while protecting the structure itself, since persons were considered to have a soul and therefore capable of negligence and able to be excommunicated.

In the common law tradition, only a person could possess legal rights. To allow them to function, the legal personality of a corporation was established to include five legal rights—the right to a common treasury or chest (including the right to own property), the right to a corporate seal (i.e., the right to make and sign contracts), the right to sue and be sued (to enforce contracts), the right to hire agents (employees) and the right to make by-laws (self-governance).

There are two kinds of legal persons: 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).

Juridical persons are entities such as corporations, firms (in some jurisdictions), and many government agencies. For most purposes they are treated in law as if they were human persons.

While natural persons acquire legal personality simply by being born, juridical persons must have legal personality conferred on them by a legal process and, for this reason, 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, legal personhood may result from legislation, such as the manner in which the Charity Commission was created in the UK.

Humans have legal personhood, and it is as a rule gained upon birth, though legal capacity, a related concept, for some acts may be age-restricted. In Civil Law countries, legal personhood is regulated by the jurisdictions Civil code, like the Code civil of France.

Some international human rights documents and treaties recognise the right to be recognised as a legal person as an individual human right. Examples include Article 6 of the Universal Declaration of Human Rights or Article 3 the American Convention on Human Rights. This serves to prevent humans being stripped of their legal personality, as, for example, slaves were under some systems of slavery. Entities not considered persons would instead be understood as objects, and would be subject to property rights, as slaves were.

Nowak considers this right to be one of the rare absolute human rights (meaning it is not possible to restrict it in any way), and additionally non-derogable.

The United Nations Sustainable Development Goal 16 advocates for the provision of legal identity for all natural persons, including birth registration by 2030 as part of the 2030 Agenda.

Artificial personality, juridical personality, or juristic personality is the characteristic of a non-living entity regarded by law as having the status of personhood.

A juridical or artificial person (Latin: persona ficta; also juristic person) has a legal name and has certain rights, protections, privileges, responsibilities, and liabilities in law, similar to those of a natural person. The concept of a juridical person is a fundamental legal fiction. It is pertinent to the philosophy of law, as it is essential to laws affecting a corporation (corporations law).

Juridical personhood allows one or more natural persons (universitas personarum) to act as a single entity (body corporate) for legal purposes. In many jurisdictions, artificial personality allows that entity to be considered under law separately from its individual members (for example in a company limited by shares, its shareholders). They may sue and be sued, enter into contracts, incur debt, and own property. Entities with legal personality may also be subjected to certain legal obligations, such as the payment of taxes.

An entity with legal personality may shield its members from personal liability.