Blitz, German for "lightning", may refer to:

• The Blitz, the German aerial campaign against Britain in the Second World War

Blitz! is a musical by Lionel Bart. The musical, described by Steven Suskin as "massive", was set in the East End of London during the Blitz (the aerial bombings during World War II). The story drew on Bart's childhood memories of London's Jewish East End during the Blitz and, like most musicals, centred on a romance between a young couple, in this case a Jewish woman and a Cockney man, although the largest role and main point-of-view character is that of Mrs. Blitztein, the young woman's mother. Steven Suskin describes it as "Abie's Irish Rose set against the burning of Atlanta." Bart himself described the play as "…three human stories inside an epic canvas; the major human conflict—the major plot—personifies the spirit of London and how that spirit developed during the period of the piece."

Blitz++ is a high-performance vector mathematics library written in C++. This library is intended for use in scientific applications that might otherwise be implemented with Fortran or MATLAB.