Classical liberalism is the philosophy committed to the ideal of limited government, constitutionalism, rule of law, due process, and liberty of individuals including freedom of religion, speech, press, assembly, and free markets.

Classical liberalism developed in the 19th century in Europe and the United States. Although classical liberalism built on ideas that had already developed by the end of the 18th century, it advocated a specific kind of society, government and public policy as a response to the Industrial Revolution and urbanization. Notable individuals whose ideas have contributed to classical liberalism include John Locke, Jean-Baptiste Say, Thomas Malthus and David Ricardo. It drew on the economics of Adam Smith and on a belief in natural law, utilitarianism, and progress.

There was a revival of interest in classical liberalism in the 20th century led by Ludwig von Mises, Friedrich Hayek and Milton Friedman. Some call the modern development of classical liberalism "neo-classical liberalism," which argued for government to be as small as possible in order to allow the exercise of individual freedom, while some refer to all liberalism before the 20th century as classical liberalism.