The tyranny of the majority (or tyranny of the masses) is an inherent weakness to majority rule in which the majority of an electorate pursues exclusively its own objectives at the expense of those of the minority factions. This results in oppression of minority groups comparable to that of a tyrant or despot, argued John Stuart Mill in his 1859 book On Liberty.

The scenarios in which tyranny perception occurs are very specific, involving a sort of distortion of democracy preconditions:

• Centralization excess: when the centralized power of a federation make a decision that should be local, breaking with the commitment to the subsidiarity principle. Typical solutions, in this condition, are concurrent majority and supermajority rules.
• Abandonment of rationality: when, as Tocqueville remembered, a decision "which bases its claim to rule upon numbers, not upon rightness or excellence". The use of public consultation, technical consulting bodies, and other similar mechanisms help to improve rationality of decisions before voting on them. Judicial review (e.g. declaration of nullity of the decision) is the typical way after the vote.

In both cases, in a context of a nation, constitutional limits on the powers of a legislative body, and the introduction of a Bill of Rights have been used to counter the problem. A separation of powers (for example a legislative and executive majority actions subject to review by the judiciary) may also be implemented to prevent the problem from happening internally in a government.

One of the earliest occurrences of this concept can be found in Plato's dialogue Gorgias, where Callicles argues that "the makers of laws are the majority who are weak; and they make laws and distribute praises and censures with a view to themselves and to their own interests; and they terrify the stronger sort of men, and those who are able to get the better of them, in order that they may not get the better of them" (Gorgias 483).