Mann was born on June 6, 1875 in Lübeck (Germany), into a merchant family. His father passed away in 1891 and Mann moved to Munich along with his mother and siblings (among which was Heinrich, also a writer), where he worked for an insurance company. His first publications appeared in the satirical magazine Simplicissimus, and he began to work as a literary critic, selling articles and short stories to various different magazines.

In 1905 he married Katia Pringsherim, daughter of Jewish mathematician Alfred Pringsherim, with whom he had six children; at the same time he had various platonic relationships with other men, with his classmate Armin Manters and painter Paul Ehrenberg among them.

In his writings, influenced by the thoughts of Schopenhauer, the individual tends to be confronted with the surrounding environment; his first important novel was Buddenbrooks (1901), followed by prominent titles such as Tonio Kroger (1903), Death in Venice(1912), The Magic Mountain (1924), Lotte in Weimar (1939) and Doctor Faustus (1947). In 1929 he was awarded the Nobel Prize in Literature.

As the Nazi political party, led by Adolf Hitler, rose to power, Mann decided to leave the country, passing through Switzerland before settling in the United States, where he worked as college professor at Princeton University.