Equality before the law, also known as equality under the law, equality in the eyes of the law, legal equality, or legal egalitarianism, is the principle that all people must be equally protected by the law. The principle requires a systematic rule of law that observes due process to provide equal justice, and requires equal protection ensuring that no individual nor group of individuals be privileged over others by the law. Sometimes called the principle of isonomy, it arises from various philosophical questions concerning equality, fairness and justice. Equality before the law is one of the basic principles of some definitions of liberalism. It is incompatible with legal slavery.

The rule of law is a political ideal that all citizens and institutions within a country, state, or community are accountable to the same laws, including lawmakers and leaders. It is sometimes stated simply as "no one is above the law". The term rule of law is closely related to constitutionalism as well as Rechtsstaat. It refers to a political situation, not to any specific legal rule. The rule of law is defined in the Encyclopædia Britannica as "the mechanism, process, institution, practice, or norm that supports the equality of all citizens before the law, secures a nonarbitrary form of government, and more generally prevents the arbitrary use of power."