Brandoni was born in the port community of Dock Sud, located east of Avellaneda, and began his career in the entertainment industry in 1962 on stage, 1963 on television, and 1966 on film. He joined the National Comedy Theater in 1964 under the direction of Luisa Vehil, and his early years were marked by a strong foundation in the art of comedy.
Brandoni's political career began when he served as cultural policy adviser for President Raúl Alfonsín from 1983 to 1989. He was a member of the centrist Radical Civic Union (UCR) and later went on to serve as a deputy in the Argentine Chamber of Deputies from 1993 to 2001. In 2005, he ran for the Argentine Senate as a UCR candidate, but was unsuccessful. He also ran for Vice Governor of Buenos Aires Province in 2007 alongside nominee Ricardo Alfonsín, but lost.
Brandoni was married to actress Marta Bianchi and later married Monica Lopez in 2007. Throughout his extensive career, he has appeared in numerous films, television shows, and plays, including leading roles in acclaimed pictures such as La tregua (1974),Juan que reía (1976),Darse cuenta (1984),Esperando la carroza (1985),Made in Argentina (1986),Cien veces no debo (1990),Convivencia (1993),Una sombra ya pronto serás (1994),De mi barrio con amor (1995),and Los pasos perdidos (2001).
Throughout his career, Brandoni has received numerous awards and accolades, including three Martín Fierro Awards (1970, 1990, and 1993) and an Argentine Film Critics Association Silver Condor award for Best Actor for his roles in Made in Argentina and Convivencia. He has also served in various actors' guilds, including the International Federation of Actors (IFA),where he held the position of Vice President from 1974 to 2004.
