Ango Sakaguchi (坂口 安吾, Sakaguchi Ango, October 20, 1906 – February 17, 1955) was a Japanese novelist and essayist. His real name was Heigo Sakaguchi (坂口 炳五 Sakaguchi Heigo). Born in Niigata, Sakaguchi was one of a group of young Japanese writers to rise to prominence in the years immediately following Japan's defeat in World War II. As such, Ango Sakaguchi was associated with the Buraiha or 'Decadent' School (無頼派 buraiha, the school of irresponsibility and decadence), which designated a group of dissolute writers who expressed their perceived aimlessness and identity crisis of post-World War II Japan.

In 1946 he wrote his most famous essay, titled "Darakuron" ("Discourse on Decadence"), which examined the role of bushido during the war. It is widely argued that he saw postwar Japan as decadent, yet more truthful than a wartime Japan built on illusions like bushido. (The work itself does not make any claims about the meaning of decadence.)