The De Lome Letter Scandal was a political scandal that erupted in the United States in 1898. It involved the publication of a letter written by Spanish diplomat Enrique Dupuy de Lôme criticizing President William McKinley. The letter was intercepted and published by American journalist Joseph Pulitzer's New York World newspaper on February 9, 1898, setting off an international incident that contributed to the outbreak of the Spanish-American War later that year.

The content of the de Lôme letter caused outrage among Americans, who saw it as evidence that Spain had contempt for their leader and country. In his missive to fellow diplomat Segismundo Bermejo y Moncada, de Lôme wrote disparagingly about McKinley's policies towards Cuba and referred to him as "weak" and "a low politician". This prompted accusations from some quarters that Spain was attempting to interfere with US foreign policy through diplomatic means. The US government responded swiftly, demanding an apology from Spain; when none was forthcoming, they declared war against them on April 25, 1898.

The subsequent conflict lasted only four months but resulted in significant losses for both sides—more than 3200 lives were lost during this time period alone—before being brought to a close with America's victory over its Spanish foes at Santiago Bay in July 1898. While not directly responsible for starting hostilities between these two nations, there is no doubt that without the leak of this private correspondence, tensions would never have escalated so quickly or dramatically between them.