Juan Negrín López (Spanish pronunciation: [xwan neˈɣɾin]; 3 February 1892 – 12 November 1956) was a Spanish physician and politician who served as prime minister of the Second Spanish Republic. He was a leader of the Spanish Socialist Workers' Party (Spanish: Partido Socialista Obrero Español, PSOE) and of the left-leaning Popular Front government during the Spanish Civil War. He also served as finance minister. He was the last Loyalist premier of Spain (1937–1939), leading the Republican forces defeated by the Nationalists under General Francisco Franco. He was President of the Council of Ministers of the Second Spanish Republic and the Spanish Republican government in exile between 1937 and 1945. He died in exile in Paris, France.
None of the leaders of the Second Spanish Republic has been as vilified as Negrín, not only by Francoist historians but also by important sectors of the exiled Spanish Left. After the end of the civil war there was no person more hated than Negrín. The leaders of his own Socialist Party were among his detractors, including his friend and fellow socialist leader Indalecio Prieto. He has been depicted as primarily responsible for losing the civil war, ruling with a dictatorial style, yielding to Communist influence, and giving Spain's gold reserves to the Soviet Union.