A protest vote (also called a blank, null, spoiled, or "none of the above" vote) is a vote cast in an election to demonstrate dissatisfaction with the choice of candidates or the current political system. Protest voting takes a variety of forms and reflects numerous voter motivations, including political alienation. Where voting is compulsory, casting a blank vote is available for those who do not wish to choose a candidate, or to protest. Unlike abstention elsewhere, blank votes are counted.

Along with abstention, or not voting, protest voting is a sign of unhappiness with available options. If protest vote takes the form of a blank vote, it may or may not be tallied into final results. Protest votes may be considered spoiled or, depending on the electoral system, counted as "none of the above" votes.