The American author known for his work "The Great Gatsby" is F. Scott Fitzgerald. Published in 1925, the novel is set in the Jazz Age and explores themes of wealth, love, and the American Dream. Through the tragic story of Jay Gatsby, Fitzgerald critiques the moral decadence and social stratification of the time. His lyrical style and vivid portrayal of the era have solidified "The Great Gatsby" as a classic of American literature, reflecting both the aspirations and disillusionments of the 1920s.