Guido et Ginevra, ou La Peste de Florence (French: Guido and Ginevra, or the Plague at Florence) is a grand opera in five acts by Fromental Halévy to a libretto by Eugène Scribe. It was premiered on 5 March 1838 by the Paris Opera at the Salle Le Peletier.

Guido et Ginevra was only a moderate success for Halévy, not nearly as applauded as his previous grand opera La Juive (1835) or as La reine de Chypre which followed it (1841). However, after its premiere it was soon played in all the major European centres. When the opera was revived in Paris in 1840 it was cut to four acts. It was translated into Italian and performed in three acts by the Théâtre-Italien at the Salle Ventadour beginning on 17 February 1870.^[1] It was performed in German in Mannheim beginning on 3 April 1879, and Hamburg, on 20 March 1882.^[2] No recent productions are known.

The opera contains touches of the composer's innovative orchestration, with a mélophone in Act II, and with Ginevra's tomb scene set to dark woodwind and brass instruments using diminished seventh harmonies.

Scribe drew the elements of his plot from the history of Florence by Louis-Charles Delécluze