Cabaret is a 1966 musical with music by John Kander, lyrics by Fred Ebb, and book by Joe Masteroff. The musical was based on John Van Druten's 1951 play I Am a Camera which was adapted from Goodbye to Berlin (1939), a semi-autobiographical novel by Anglo-American writer Christopher Isherwood which drew upon his experiences in the poverty-stricken Weimar Republic and his intimate friendship with nineteen-year-old cabaret singer Jean Ross.

Set in 1929–1930 Berlin during the twilight of the Jazz Age as the Nazis are ascending to power, the musical focuses on the hedonistic nightlife at the seedy Kit Kat Klub and revolves around American writer Clifford Bradshaw's relations with English cabaret performer Sally Bowles. A subplot involves the doomed romance between German boarding house owner Fräulein Schneider and her elderly suitor Herr Schultz, a Jewish fruit vendor.

Overseeing the action is the Master of Ceremonies at the Kit Kat Klub, and the club itself serves as a metaphor for ominous political developments in late Weimar Germany. The musical depicts Weimar-era Berlin during this chaotic interwar period as a carnival of debauchery and despair inhabited by desperate people who are unaware of the national catastrophe that awaits them.

The original Broadway production opened on November 20, 1966, at the Broadhurst Theatre in New York City and became a box office hit that ran for 1,166 performances. The award-winning musical inspired numerous subsequent productions in London and New York as well as the 1972 film of the same name.