In economics, laissez-faire (English pronunciation: /ˌlɛseɪˈfɛər/ ( listen), French: [lɛsefɛʁ] ( listen)) means allowing industry to be free from state intervention, especially restrictions in the form of tariffs and government monopolies. The phrase is French and literally means "let do", but it broadly implies "let it be", or "leave it alone."

Laissez faire, telle devrait être la devise de toute puissance publique, depuis que le monde est civilisé ... Détestable principe que celui de ne vouloir grandir que par l'abaissement de nos voisins! Il n'y a que la méchanceté et la malignité du coeur de satisfaites dans ce principe, et l’intérêt y est opposé. Laissez faire, morbleu! Laissez faire!!

(Laissez faire, this should be the motto of all public power, since the world is civilized ... Detestable principle that will not grow through the lowering of our neighbors! Only malice and malignity of heart satisfied in principle and interest is opposed. Leave it, damn it! Laissez faire!)

According to historical myths, the phrase stems from a meeting in about 1680 between the powerful French finance minister Jean-Baptiste Colbert and a group of French businessmen led by a certain M. Le Gendre. When the eager mercantilist minister asked how the French state could be of service to the merchants, Le Gendre replied simply "Laissez-nous faire" ("Leave us be", lit. "Let us do").

The laissez faire slogan was popularised by Vincent de Gournay, a French intendant of commerce in the 1750s. Gournay was an ardent proponent of the removal of restrictions on trade and the deregulation of industry and economic prosperity in France. Gournay was delighted by the LeGendre anecdote, and forged it into a larger maxim all his own: "Laissez faire et laissez passer" ('Let do and let pass'). His motto has also been identified as the longer "Laissez faire et laissez passer, le monde va de lui même!" ("Let do and let pass, the world goes on by itself!"). Although Gournay left no written tracts on his economic policy ideas, he had immense personal influence on the thinking of his contemporaries, notably the physiocrats, who credit both the laissez-faire slogan and doctrine to Gournay.

Before Gournay, P.S. de Boisguilbert had enunciated the phrase "on laisse faire la nature" ('let nature run its course'). Laissez-faire was one of a number of French "free trade" and "non-interference" slogans coined in the 17th century. D'Argenson, during this time, was better known for the similar but less-celebrated motto "Pas trop gouverner" ("Govern not too much").

The first known English-language use of "laissez faire" in economics was in 1774, by George Whatley, in the book Principles of Trade, which was co-authored with Benjamin Franklin. Notably, classical economists, such as Thomas Malthus, Adam Smith and David Ricardo, did not use the term. Jeremy Bentham used the term, but only with the advent of the Anti-Corn Law League did the term receive much of its (English) meaning. Nonetheless, it was probably James Mill's reference to the "laissez-faire" maxim (together with "pas trop gouverner") in an 1824 entry for Encyclopædia Britannica that really brought the term into wider English usage.

Adam Smith first used the metaphor of an "invisible hand" in his book The Theory of Moral Sentiments to describe the unintentional effects of economic self organization from economic self interest. Some have characterized this metaphor as one for laissez-faire, but Smith himself never used the term, and likely intended something somewhat different.