Elgueta Becker was born in Reñihue, Chiloé, on 20 February 1921, the son of Baldomero Elgueta and Clotilde Becker.[1] He married Yolanda Pinto Miranda, with whom he had three children.[1]
He studied at the high schools of Osorno and Ancud, and later entered the Law School of the University of Chile.[1] He worked for the Empresa Nacional de Fundiciones, and began his working life in 1942 in the Civil Registry Archives. Between 1943 and 1946 he worked in activities related to his legal studies, and from 1946 to 1953 served as teacher and inspector of the Escuela Industrial de Hoteleros.[1]
His political life began in 1937, when he joined the Socialist Youth. He served as sectional secretary in Ancud (1938); delegate to the General Congress held in Talca (1940); head of the Socialist Party University Brigade (1943); and member of the Central Committee of the Socialist Youth (1944). He also joined the Central Committee at the XII Congress held in Concepción (1946); at the XIII Congress in Valparaíso (1948); and at the XIV Congress in Chillán (1952).[1] Within the Party, he was responsible for political education and propaganda, founding and directing the magazine «Espartaco» (1946–1947); directing the weekly «Consigna» (1947–1948); and serving as director of the weekly «La Calle» in 1953.[1]
He was elected Deputy for the 25th Departamental Group (Ancud, Castro and Quinchao) for the 1953–1957 legislative term, representing the Popular Socialist Party, serving on the Permanent Committee on Agriculture and Colonization.[1] He became the first person born in Chiloé to be elected Deputy for that region since 1925.[1]
He was also a member of the Instituto Chileno Israelí de Cultura.[1]
Elgueta died on 2 May 2025, at the age of 86.[2]