He was the son of Carlos Onetti, a customs official, and Honoria Borges, who belonged to a Brazilian aristocratic family from the state of Rio Grande do Sul.

[2] A high school drop-out, Onetti's first novel, El pozo, published in 1939,[3] met with his close friends' immediate acclaim, as well as from some writers and journalists of his time.

He was considered a senior member of the 'Generation of 45', a Uruguayan intellectual and literary movement: Carlos Maggi, Manuel Flores Mora, Ángel Rama, Emir Rodríguez Monegal, Idea Vilariño, Carlos Real de Azúa, Mauricio Muller, José Pedro Díaz, Amanda Berenguer, Mario Benedetti, Ida Vitale, Líber Falco, among others.

Their crime: as members of the jury, they had chosen Nelson Marra's short story El guardaespaldas (i.e. "The bodyguard") as the winner of Marcha's annual literary contest.

[10] Source:[13] Uruguayan director Alvaro Brechner adapted "Jacob y el Otro" for his 2009 film Bad day to go fishing ("Mal día para pescar").