Galeano, whose 1971 essay "Open Veins of Latin America" is considered by many leftists to be the seminal history of the region, was hospitalised last week in the Uruguayan capital Montevideo, said officials at the CASMU hospital.
He had been suffering from lung cancer.
Galeano's work blended various genres, including journalism, fiction, essays and the drawings he used to illustrate works such as "The Book of Embraces," a collection of vignettes charged with politics and lyrical prose.
Born September 3, 1940, Galeano never finished high school, but learned the writing craft hanging out in Montevideo's old cafes, he said.
Also Read
He began his journalistic career at 14 years old, publishing a caricature in the Socialist Party's weekly newspaper El Sol.
He went on to become the editor of prestigious magazine Marcha in 1961, working under its founder, Carlos Quijano, to publish authors such as fellow Uruguayan great Mario Benedetti.
Throughout this turbulent period of leftist rebellions and brutal dictatorships across Latin America, Galeano continued documenting the region's turmoils from afar, publishing the first two installments of his "Memory of Fire" trilogy, which narrates the history of the Americas.
He returned to Uruguay after democracy was restored in 1985, and lived to see the leftwing Broad Front (FA) party come to power in 2005.