Carlos Castillo Armas (locally ['kaɾlos kas'tiʝo 'aɾmas]; 4 November 1914 – 26 July 1957) was a Guatemalan military officer and politician who was the 28th president of Guatemala, serving from 1954 to 1957 after taking power in a coup d'état. A member of the far-right National Liberation Movement (MLN) party, his authoritarian government was closely allied with the United States.
Born to a planter, out of wedlock, Castillo Armas was educated at Guatemala's military academy. A protégé of Colonel Francisco Javier Arana, he joined Arana's forces during the 1944 uprising against President Federico Ponce Vaides. This began the Guatemalan Revolution and the introduction of representative democracy to the country. Castillo Armas joined the General Staff and became director of the military academy. Arana and Castillo Armas opposed the newly elected government of Juan José Arévalo; after Arana's failed 1949 coup, Castillo Armas went into exile in Honduras. Seeking support for another revolt, he came to the attention of the US Central Intelligence Agency (CIA). In 1950 he launched a failed assault on Guatemala City, before escaping back to Honduras. Influenced by lobbying by the United Fruit Company and Cold War fears of communism, in 1952 the US government of President Harry Truman authorized Operation PBFortune, a plot to overthrow Arévalo's successor, President Jacobo Árbenz. Castillo Armas was to lead the coup, but the plan was abandoned before being revived in a new form by US President Dwight D. Eisenhower in 1953.