 Political legitimacy is a virtue of political institutions and of the decisions—about laws, policies, and candidates for political office—made within them. This entry will survey the main answers that have been given to the following questions. First, how should legitimacy be defined? Is it primarily a descriptive or a normative concept? If legitimacy is understood normatively, what does it entail? Some associate legitimacy with the justification of coercive power and with the creation of political authority. Others associate it with the justification, or at least the sanctioning, of existing political authority. Authority stands for a right to rule—a right to issue commands and, possibly, to enforce these commands using coercive power. An additional question is whether legitimate political authority is understood to entail political obligations or not. Most people probably think it does. But some think that the moral obligation to obey political authority can be separated from an account of legitimate authority, or at least that such obligations arise only if further conditions hold.