Dietrich Bonhoeffer (German: [ˈdiːtʁɪç ˈbɔn.høː.fɐ] (listen); 4 February 1906 – 9 April 1945) was a German Lutheran pastor, theologian, anti-Nazi dissident, and key founding member of the Confessing Church. His writings on Christianity's role in the secular world have become widely influential, and his book The Cost of Discipleship is described as a modern classic.Apart from his theological writings, Bonhoeffer was known for his staunch resistance to the Nazi dictatorship, including vocal opposition to Hitler's euthanasia program and genocidal persecution of the Jews. He was arrested in April 1943 by the Gestapo and imprisoned at Tegel prison for one and a half years. Later, he was transferred to Flossenbürg concentration camp.

Bonhoeffer was accused of being associated with the 20 July plot to assassinate Adolf Hitler and was then quickly tried along with other accused plotters, including former members of the Abwehr (the German Military Intelligence Office). He was hanged on 9 April 1945 as the Nazi regime was collapsing.