A state of emergency is a governmental declaration that may suspend some normal functions of the executive, legislative and judicial powers, alert citizens to change their normal behaviours, or order government agencies to implement emergency preparedness plans. It can also be used as a rationale for suspending rights and freedoms, even if guaranteed under the constitution. Such declarations usually come during a time of natural or man made disaster, during periods of civil unrest, or following a declaration of war or situation of international or internal armed conflict. Justitium is its equivalent in Roman law.

A state of emergency is a governmental declaration that announces that the country is in a state of emergency.