Rebellion, uprising, or insurrection is a refusal of obedience or order. It refers to the open resistance against the orders of an established authority.

A rebellion originates from a sentiment of indignation and disapproval of a situation and then manifests itself by the refusal to submit or to obey the authority responsible for this situation. Rebellion can be individual or collective, peaceful (civil disobedience, civil resistance, and nonviolent resistance) or violent (terrorism and guerrilla warfare).

Rebellion and revolt are often distinguished by their different aims. While rebellion generally seeks to evade and/or gain concessions from an oppressive power, a revolt seeks to overthrow and destroy that power, as well as its accompanying laws. The goal of rebellion is resistance while a revolt seeks a revolution. As power shifts relative to the external adversary, or power shifts within a mixed coalition, or positions harden or soften on either side, an insurrection may seesaw between the two forms.