Il diluvio universale (The great flood) is an azione tragico-sacra, or opera, by Gaetano Donizetti.

The Italian libretto was written by Domenico Gilardoni after Lord Byron's Heaven and Earth and Francesco Ringhieri's tragedy Il diluvio (1788).

The first production in Switzerland took place at St. Gallen where, since 2006, an opera is presented in the open air in front of the Cathedral around the first weekend of July.

[5] The production of Il diluvio was also given at the St. Galler Festspiele 2010 when Mirco Palazzi, Majella Cullagh and Manuela Custer appeared.

[6] In 2023 a new production was given at Festival Donizetti in Bergamo with Riccardo Frizza as director and Nahuel di Pierro, Susanna Gianfaldoni and Enea Scala performing in the main roles.