- Date: 14th century
- an official entrusted with administration of the laws: as a : a principal official exercising governmental powers over a major political unit (as a nation)
- b : a local official exercising administrative and often judicial functions
- c : a local judiciary official having limited original jurisdiction especially in criminal cases
A magistrate is a judicial officer; in ancient Rome, the word magistratus denoted one of the highest government officers with judicial and executive powers. Today, in common law systems, a magistrate has limited law enforcement and administration authority. In civil law systems, a magistrate might be a judge in a superior court; the magistrate's court might have jurisdiction over civil cases and criminal cases. A related, but not always equivalent, term is Chief Magistrate, which can (historically) denote political and administrative officers.
In ancient Rome, the word magistratus referred to one of the highest offices of state, and analogous offices in the local authorities such as municipium, which were subordinate only to the legislature of which they generally were members, often even ex officio, and often combined judicial and executive power, together constituting one jurisdiction. In Rome itself, the highest magistrates were members of the so-called cursus honorum -'career of honors'. They held both judicial and executive power within their sphere of responsibility (hence the modern use of the term "magistrate" to denote both judicial and executive officers), and also had the power to issue ius honorarium, or magisterial law. The Praetor (the office was later divided into two, the Urban and Peregrine Praetors) was the highest judge in matters of private law between individual citizens, while the Curule Aediles, who supervised public works in the city, exercised a limited civil jurisdiction in relation to the market. Roman magistrates were not lawyers, but were advised by jurists who were experts in the law.
The term was maintained in most feudal successor states to the western Roman Empire, mainly Germanic kingdoms, especially in city-states, where the term magistrate was also used as an abstract generic term, denoting the highest office, regardless of the formal titles (e.g. Consul, Mayor, Doge), even when that was actually a council. The term "chief magistrate" applied to the highest official, in sovereign entities the head of state and/or head of government.