Gustave de Molinari (3 March 1819 – 28 January 1912) was a political economist and classical liberal theorist born in Liège, in the Walloon region of Belgium, and was associated with French laissez-faire economists such as Frédéric Bastiat and Hippolyte Castille. Living in Paris during the 1840s, he participated with the Ligue pour la Liberté des Échanges (Free Trade League), based on the theories of Frédéric Bastiat.