Des Simplicius Simplicissimus Jugend is a German-language opera by Karl Amadeus Hartmann to a libretto by Hermann Scherchen, Wolfgang Petzet and the composer after Jakob von Grimmelhausen's picaresque novel Simplicius Simplicissimus. The opera was written 1934-1935 structured in three acts and more scenes, to which was added in 1939 an overture in homage to Prokofiev, and premiered in 1948. It was extensively revised as Simplicius Simplicissimus in 1957.
The title role of the Simplicius, a naive shepherd boy is sung by a soprano, the Einsiedler is sung by a baritone.