Baldomero Lillo (6 January 1867, in Lota, Chile – 10 September 1923, in San Bernardo, Chile^[1]) was a Chilean Naturalist author, whose works had social protest as their main theme.

Lillo's father traveled to California to participate in the 1848 Gold Rush, but returned with no fortune. He did learn much about mining, and he moved to southern Chile, Lota, to work the coal mines. Baldomero Lillo grew up in these mining communities and worked the mines himself. He was exposed to the writings of the French author Émile Zola, who used the philosophy of Positivism and the literary current of Naturalism to try to change the terrible conditions of French coal miners. Lillo was able to observe similar conditions in the Chilean mines and set out to improve the conditions of the workers by dramatizing their plight. Lillo wrote many short stories (collected in two major books, Sub Sole and Sub Terra) which sparked the interest of social activists who were appalled by the conditions in the mines.

• Adams, Nicholson B., et al. Hispanoamérica en su literatura. (2nd ed.) New York: W. W. Norton, 1993, pp. 225–234.
• Chang-Rodríguez, Raquel. Voces de Hispanoamérica. Boston: Heinle & Heinle, 2004, pp. 258–267.
• Child, Jack. Introduction to Latin American Literature: a Bilingual Anthology. Lanham: University Press of America,1994, pp. 197–210.
• Englekirk, John E. An Outline History of Spanish American Literature. New York: Appleton-Century-Crofts, 1965, pp. 92–93.
• Mujica, Bárbara. Texto y vida: introducción à la literatura hispanoamericana. New York: Harcourt Brace Jovanovich, 1992 p. 343.

• Works by or about Baldomero Lillo at the Internet Archive
• Works by Baldomero Lillo at LibriVox (public domain audiobooks)