Security of the person is a basic entitlement guaranteed by the Universal Declaration of Human Rights, adopted by the United Nations in 1948. It is also a human right explicitly mentioned and protected by the Constitution of Canada, the Constitution of South Africa and other laws around the world.

In general, the right to the security of one's person is associated with liberty and includes the right, if one is imprisoned unlawfully, to the remedy of habeas corpus. Security of person can also be seen as an expansion of rights based on prohibitions of torture and cruel and unusual punishment. Rights to security of person can guard against less lethal conduct, and can be used in regard to prisoners' rights.

The right to security of the person is guaranteed by Article 3 of the Universal Declaration of Human Rights. In this article, it is combined with the right to life and liberty. In full, the article reads, "Everyone has the right to life, liberty and security of person."

The United Nations treaty, the International Covenant on Civil and Political Rights (1966), also recognizes a right to security of person. Article 9(1) states that "Everyone has the right to liberty and security of person," and the section prohibits "arbitrary arrest or detention." The section continues, "No one shall be deprived of his liberty except on such grounds and in accordance with such procedure as are established by law."

A person is a being, such as a human, that has certain capacities or attributes constituting personhood, the precise definition of which is the subject of much controversy.^{[vague language]} The common plural of "person", "people", is often used to refer to an entire nation or ethnic group (as in "a people"), so the plural "persons" is often used in contexts which require precision such as philosophical and legal writing.

In ancient Rome, the word "persona" (Latin) or "prosopon" (πρόσωπον: Greek) originally referred to the masks worn by actors on stage. The various masks represented the various "personae" in the stage play, while the masks themselves helped the actor's voice resonate and made it easier for the audience to hear.

In Roman law, the word "persona" became used to refer to a role played in court, and it became established that it was the role rather than the actor that could have rights, powers, and duties, because different individuals could assume the same roles, the rights, powers, and duties followed the role rather than the actor, and each individual could act in more than one role, each a different "person" in law.^{[tortured english][citation needed]}