Libertarian may refer to:
- A proponent of libertarianism, a political philosophy that upholds individual liberty, especially freedom of expression and action
- A member of Libertarian Party (United States) or other libertarian political party; see: List of libertarian political parties
- A member or supporter of a libertarian organization; see: List of libertarian organizations
- Libertarianism (metaphysics), one of the main philosophical positions related to the problems of free will and determinism