Jean-Louis de Lolme (1741–1804) was a Swiss and English political theorist. He was born in Geneva and became an advocate there. Criticism of the political authorities led him to seek refuge in England, where he lived as an author and journalist. Toward the end of his life he returned to Geneva and was elected to the Council of Two Hundred.
His most famous work is the Constitution de l'Angleterre, which appeared in English as The Constitution of England (1771 in French, and later editions in English) In this book, he advocated a constitutional form of government enshrining the principle of balanced government, balancing the one, the few, and the many, or the ideas of monarchy, aristocracy, and democracy. De Lolme extolled the British government because, in his view (influenced by his own observations and study as well as by the previous writings of Voltaire and Montesquieu), the unwritten constitution of government of Great Britain embodied the ideal of balanced government better than any other government of the time. De Lolme in particular praised the elements of representative democracy in the unwritten English constitution, and urged an extension of the suffrage. He developed and refined his political thinking to a large extent in opposition to the more radical theory of direct democracy advocated by his compatriot, Jean-Jacques Rousseau, whom de Lolme accused of being unrealistic. De Lolme is sometimes identified as a probable candidate for being the person behind the pseudonymous political commentator Junius.
De Lolme influenced many of the framers of the American constitution. One founding father who was not present in Philadelphia but whose Defense of the Constitutions of Government of the United States influenced the delegates there was John Adams, who praised De Lolme's book as one of the best on the subject of constitutionalism ever written. Some have argued that De Lolme's work also influenced the Constitution of Norway.