A dictator is a political leader who possesses absolute power and wields it in an oppressive or abusive manner. A state ruled by a dictator is called a dictatorship. The word originated as the title of a magistrate in the Roman Republic appointed by the Senate to rule the republic in times of emergency (see Roman dictator and justitium).

Like the term “tyrant” (which was originally a respectable Ancient Greek title), and to a lesser degree “autocrat“, “dictator” came to be used almost exclusively as a non-titular term for oppressive, even abusive rule, yet it had rare modern titular use.

In modern usage, the term “dictator” is generally used to describe a leader who holds and/or abuses an extraordinary amount of personal power, especially the power to make laws without effective restraint by a legislative assembly^{[not verified in body]}. Dictatorships are often characterised by some of the following traits: suspension of elections and civil liberties; proclamation of a state of emergency; rule by decree; repression of political opponents without abiding by the rule of law procedures; these include one-party state, and cult of personality.