In political science, minoritarianism (or minorityism) is a neologism for a political structure or process in which a minority group of a population has a certain degree of primacy in that population's decision making, with legislative power or judicial power being held or controlled by a minority group rather than a majority that is representative of the population. Minoritarianism is sometimes used to describe minority rule, rule by a dominant minority such as an ethnic group delineated by religion, language, or some other identifying factor.

Minoritarianism is most often applied disparagingly to processes in which a minority is able to block legislative changes in the presence of supermajority threshold requirements.^{[citation needed]} For example, if a two-thirds majority vote in favor is required to enact a new law, an opposing minority of greater than one-third is said to have "minoritarian" powers.

Even in the case where minority control is nominally limited to blocking the majority with veto power (whether as a result of a supermajority requirement or consensus decision-making), this may result in the situation where the minority retains effective control over the group's agenda and the nature of the proposals submitted to the group, as the majority would be disinclined to propose ideas that they know the minority would veto.

Critics of this use of minoritarianism argue that the ability to block legislation is substantially different from the ability to enact new legislation against the will of the majority, making the analogy to unpopular "dominant minority rule" examples inappropriate.

Minoritarianism may be used to describe cases where appeasement of minorities by votebank politics is practiced. Examples include but are not limited to, Indian Muslims and Francophone Canadians.

Supermajority decision threshold requirements are often found in small deliberative groups where these requirements are sometimes adopted in an attempt to increase protection of varied interests within the group. The requirements may be formally stated or may be unstated (for example, when an organization is described as having a "consensus culture").

A common criticism of consensus decision-making is that it can lead to a situation wherein a minority can block the will of the majority. Consensus advocates argue that this is a good feature—that no action is preferable to one without the consensus support of the group.

Attempts to resolve the dilemma through formal supermajority standards are generally discouraged by parliamentary authorities: