The Bunker, also published as The Berlin Bunker, is a 1975 account, written by American journalist James P. O'Donnell and German journalist Uwe Bahnsen, as to the history of the Führerbunker in 1945, as well as the last days of German dictator Adolf Hitler. The English edition was first published in 1978. Unlike other accounts O'Donnell focused considerable time on other, less-famous, residents of the bunker complex. Additionally, unlike the more academic works by historians, the book takes a journalistic approach. The book was later used as the basis for a 1981 CBS television film of the same name.

The Führerbunker was an air raid shelter located near the Reich Chancellery in Berlin, Germany. It was part of a subterranean bunker complex constructed in two phases in 1936 and 1944. It was the last of the Führer Headquarters (Führerhauptquartiere) used by Adolf Hitler during World War II.