A protest is an expression of objection, by words or by actions, to particular events, policies or situations. Protests can take many different forms, from individual statements to mass demonstrations. Protesters may organize a protest as a way of publicly making their opinions heard in an attempt to influence public opinion or government policy, or they may undertake direct action in an attempt to directly enact desired changes themselves. Where protests are part of a systematic and peaceful campaign to achieve a particular objective, and involve the use of pressure as well as persuasion, they go beyond mere protest and may be better described as cases of civil resistance or nonviolent resistance.

Various forms of self-expression and protest are sometimes restricted by governmental policy, economic circumstances, religious orthodoxy, social structures, or media monopoly. When such restrictions occur, protests may assume the form of open civil disobedience, more subtle forms of resistance against the restrictions, or may spill over into other areas such as culture and emigration.

A protest can itself sometimes be the subject of a counter-protest. In such a case, counter-protesters demonstrate their support for the person, policy, action, etc. that is the subject of the original protest.