Philipp Bouhler (11 September 1899 – 19 May 1945) was a German senior Nazi Party functionary who was both a Reichsleiter (National Leader) and Chief of the Chancellery of the Führer of the NSDAP. He was also the SS official responsible for the Aktion T4 euthanasia program that killed more than 250,000 disabled adults and children in Nazi Germany, as well as co-initiator of Aktion 14f13, also called "Sonderbehandlung" ("special treatment"), that killed 15,000–20,000 concentration camp prisoners.