Diosdado Pangan Macapagal (September 28, 1910 - April 21, 1997) was a politician from the Philippines. He was elected President of the Philippines in 1961 by a coalition of liberals and progressives. He focused on fighting corruption and graft in the government. Seeking to stimulate economic development, he took the advice of wealthy supporters and allowed the Philippine peso to float on the free currency exchange market. This policy bled millions of pesos from the government's treasury each year during his administration. His reform efforts were blocked by the Nacionalistas who dominated the House of Representatives and the Senate at that time. In 1965, he was defeated in the presidential election by Ferdinand Marcos.
Before his political career started, he was a lawyer in Manila. He aided the resistance against the Japanese occupiers during World War II. In 1948 he served as second secretary to the Philippine Embassy in Washington, DC. In 1949 he was elected to the House of Representatives, where he served until 1956. During that time, he was the Philippines' representative to the United Nations General Assembly three times. In 1957, as a member of the Liberal Party, he became vice president under President Carlos Garcia of the Nacionalista Party.
In 1979 he formed the National Union for Liberation to oppose the Marcos regime. His daughter, Gloria Macapagal-Arroyo, is the current president of the Philippines and won a second term after the May 10, 2004 election.