Giuseppina Ronzi de Begnis (born Giuseppina Ronzi; Milan 11 January 1800 – died, Florence, 7 June 1853) was an Italian soprano opera singer famous for the roles written for her by the prominent composers of the 1820s and 1830s. Her father, Gaspare, was a prominent ballet dancer and choreographer, and her mother, Antonia, a ballerina. Her brothers Stanislao and Pollione were opera singers. As a singer, she made her debut in Naples at the Teatro dei Fiorentini in 1814 in Giovanni Cordella's L'Avaro, followed by important engagements in Bologna in 1816, also appearing in Genoa, Florence; in 1817 as Giulia La Vestale, and in Bergamo. She married Italian bass Giuseppe de Begnis (1793–1849) when she was only 16. The marriage lasted only a few years and the two separated in 1825.
Her figure has been described by her contemporaries, including Donizetti, as fat and voluptuous; a critic of Teatri di Milano wrote that "Ronzi was nevertheless a very beautiful figure on the stage, and for those who are not enemies of the flesh, she was very beautiful."
Shortly after her arrival in Paris, in August 1819, she became incensed when she learned that she was expected to sing Donna Anna in the upcoming production of Don Giovanni at the Opera instead of Zerlina. Ronzi was also known for her capricious attitudes and for having confrontations and arguments with female colleagues, including the famous altercation with Anna Del Sere during the rehearsals of Maria Stuarda. The two leading ladies took the heated match between the two crowned heads a step further, and when Ronzi over-emphasized her response to Elisabetta with the famous “Vil bastarda” insult, a raging fight ensued. Donizetti might have fuelled the animosity between the two primadonnas when in response to an overheard comment by Ronzi that he “protected that whore of a Del Sere” he responded that he protected neither of them. Afterwards adding that "those two queens were whores, and you two are equally whores":
The incident was highly publicized and generated a scandal that prompted the censors to ban the libretto forcing Donizetti to make a last-minute change to the libretto and story-line to fit his music to a story of Florentine feuds in the 1200s re-titled Buondelmonte.