Sweeney Todd is a fictional character who first appeared as the villain of the Victorian penny dreadful serial The String of Pearls (1846–47). The original tale became a staple of Victorian melodrama and London urban legend. A barber from Fleet Street, Todd murders his customers with a straight razor and turns their bodies over to Mrs. Lovett, his partner in crime, who bakes their flesh into meat pies. The tale has been retold many times since in various media, most notably in the Tony award–winning Broadway musical by Stephen Sondheim and Hugh Wheeler. The musical, based on Christopher Bond's 1973 play of the same name, significantly deepened Todd’s character. It depicts him as former prisoner Benjamin Barker, who becomes obsessed with murdering Turpin, the judge who unjustly convicted him and destroyed his family.

Claims that Sweeney Todd was a historical person are strongly disputed by scholars, although possible legendary prototypes exist.