Alexis-Charles-Henri Clérel de Tocqueville (French: [alɛksi(s) ʃaʁl ɑ̃ʁi kleʁɛl də tɔkvil]; 29 July 1805 – 16 April 1859) was a French political thinker and historian best known for his Democracy in America (appearing in two volumes: 1835 and 1840) and The Old Regime and the Revolution (1856). In both of these works, he analyzed the rising living standards and social conditions of individuals and their relationship to the market and state in Western societies. Democracy in America (1835), his major work, published after his travels in the United States, is today considered an early work of sociology and political science.

An eminent representative of the classical liberal political tradition, Tocqueville was an active participant in French politics, first under the July Monarchy (1830–1848) and then during the Second Republic (1849–1851) which succeeded the February 1848 Revolution. He retired from political life after Louis Napoléon Bonaparte's 2 December 1851 coup, and thereafter began work on The Old Regime and the Revolution, Volume I.

The Old Regime and the Revolution is Alexis de Tocqueville's great meditation on the origins and meanings of the French Revolution. One of the most profound and influential studies of this pivotal event, it remains a relevant and stimulating discussion of the problem of preserving individual and political freedom in the modern world. Alan Kahan's translation provides a faithful, readable rendering of Tocqueville's last masterpiece, and it includes notes and variants which reveal Tocqueville's sources and include excerpts from his drafts and revisions. The introduction by France's most eminent scholars of Tocqueville and the French Revolution, Francoise Melonio and the late Francois Furet, provides a brilliant analysis of the work.