Fernando Sergio Marcelo Marcos Belaúnde Terry (October 7, 1912 – June 4, 2002) was a Peruvian politician who twice served as President of Peru (1963–1968 and 1980–1985). Deposed by a military coup in 1968, he was re-elected in 1980 after twelve years of military rule.

The second of four children, Belaúnde was born in Lima into a wealthy aristocratic family of Spanish forebears: his father, Rafael Belaúnde Diez Canseco (1886–1972), a professor, served as Prime Minister under José Bustamante y Rivero; his paternal grandfather, Mariano Andrés Belaunde, was a Finance Minister; and one of his great-grandfathers, Pedro Diez Canseco, was also President of the Republic. He attended the Sagrados Corazones Recoleta in Lima.

During the dictatorship of Augusto B. Leguía, the persecution for the political activities of his father Rafael and his uncle Víctor Andrés Belaúnde prompted the family to move to France in 1924, where Fernando attended high school and received his initial University education in engineering.

From 1930 to 1935, Belaúnde studied architecture in the United States, where he first attended the University of Miami (where his father was also teaching), and in 1935 transferred to the University of Texas at Austin, where he obtained his degree as an architect. He would later become pro-American and became very proficient in the English language, with some referring to him as "Fred Blundy".

He later moved to Mexico and worked as an architect for a brief time, but returned to Peru in 1936 and started his professional career as an architect designing private homes. In 1937, he started a magazine called El Arquitecto Peruano ("Peruvian Architect"), which dealt with interior design, general urbanism and housing problems the country was facing. This also gave way to the Architects Association of Peru and the Urbanism Institute of Peru.

As a result, Belaúnde also became a government public-housing consultant throughout the country and abroad. In 1943, Belaúnde began teaching architecture and urban planning at Escuela Nacional de Ingenieros of Lima and later became the dean of the Civil Engineering and Architecture department. Belaúnde also directed the construction, along with other professors and students, of the faculty of architecture of the National University of Engineering in 1955.

Belaúnde's political career began in 1944 as cofounder of the National Democratic Front party which elected José Bustamante as president in 1945; he served in the Peruvian Congress until a coup by General Manuel Odría in 1948 interrupted democratic elections.

Belaúnde returned to the political arena in 1956, when the outgoing Odría dictatorship called for elections and he led the slate submitted by the "National Front of Democratic Youth", an organization formed by reform-minded university students, some of which had studied under him; his principled support for the La Prensa newspaper, which had been closed down by the dictatorship in early 1956, had prompted the leadership of the National Front to approach him as to lead its slate.