Schirach was born in Weimar as son of the theatre director and Rittmeister Karl von Schirach and his American wife Emma. He joined a Wehrjugendgruppe (military cadet group) aged only ten and became a member of the NSDAP in 1925. He soon gained the respect of Hitler and was transferred to Munich and in 1929 became leader of the Nationalsozialistischen Deutschen Studentenbunds (NSDStB, National Socialist Students' Union). In 1931 he was a Reichsjugendführer (youth leader) in the NSDAP and in 1933 he was made head of the Hitler Jugend and given a SA rank of Gruppenführer.
In 1940 Schirach joined the army and served briefly in France before being recalled. Schirach lost control of the HJ to Arthur Axmann and Hitler instead made him Gauleiter (or Reichsstatthalter) of the Reichsgau Vienna and he remained in that post until the end of the war.
Schirach was captured in 1945 and was one of the officials put on trial at Nuremberg. At the trial Shirach was one of only two men to denounce Hitler and appear contrite before the court. (The other was Albert Speer). He said that he did not know about the extermination camps. He also provided evidence that he had protested to Martin Bormann about the inhumane treatment of the Jews. He was found guilty on October 1, 1946 of conspiring to commit "crimes againt peace" and of "crimes against humanity". He was sentenced and served twenty years in Spandau Prison.
He was released on September 30, 1966 and retired quietly to southern Germany. He published his memoirs, Ich glaubte an Hitler ("I believed in Hitler"), in 1967 and died in Kröv-an-der-Mosel.
He had married Henriette Hoffman in 1932 and they had three sons and a daughter. She divorced him in 1950 while he was in prison.