Sepúlveda was born in Talca on 1 June 1919, the son of Luis Sepúlveda Mandiola and Alicia Donoso Molina.[1] He married Alicia Garín Willigmann, with whom he had two children: María Alicia and Claudio.[1]
He studied at the Libertador Bernardo O'Higgins Military Academy before transferring to the Chilean Air Force. Over his career he served as United Nations observer in Lebanon, as Aerial Aide-de-camp to Presidents Jorge Alessandri and Eduardo Frei Montalva, as Military and Aeronautical Attaché in the United Kingdom, and as Director of the Air War Academy. He also carried out missions abroad to procure new aircraft for the Chilean Air Force.
With the rank of Brigadier General of Aviation, Sepúlveda was appointed Minister of Mining during Allende’s government, serving from November 1972 to March 1973. He was one of nine military officers who joined the cabinet of the Unidad Popular (UP).[1] After leaving the cabinet, he returned to the Air Force as Director of Instruction, and in September 1973 he was promoted to Director of Personnel and awarded the rank of General of Aviation. He retired in March 1975.
Sepúlveda died in Santiago on 29 May 1989 and was buried in the General Cemetery of Santiago.