Fanny Eckerlin (1802–1842) was an Italian mezzo-soprano who also sang contralto roles. During her career she was highly regarded, drawing favorable comparisons to Benedetta Rosmunda Pisaroni, but today she is remembered, if at all, for her association with the early career of Gaetano Donizetti, including creating the title role in his first publicly-performed opera, Enrico di Borgogna.
Eckerlin's father was a Napoleonic official of Polish origin; her mother, an Italian, was a sister of the actress Teresa Pichler , whose husband was the poet Vincenzo Monti. A native of Milan, she studied at the Milan Conservatory under David Banderali. At the age of sixteen in 1818 she made her debut in L'Italiana in Algeri of Gioacchino Rossini at the Teatro San Benedetto in Venice; it was later that same year, on November 14, that she created the title role of Donizetti's Enrico di Borgogna at the Teatro San Luca, in the same city. Her performance on this occasion was overshadowed by the indisposition, through stage fright, of the prima donna, Adelina Catalani, and the surviving review from Nuovo Osservatore Veneziano makes alsmot no mention of her appearance.
On December 15 of the following month, also at the Teatro San Luca, Eckerlin created the role of Enrico in Donizetti's Una follia, a now-lost opera buffa based on the same libretto as the previous work. She created one further role for Donizetti, that of Serafina in his comedy Le nozze in villa. That opera premiered at the Teatro Vecchio in Mantua during the carnival season of 1820–1821. It was not a success; Bartolomeo Merelli, the librettist, later blamed Eckerlin in part for its failure, writing in his Cenni biografici that the piece had faltered due to the "caprices and ill will of several of the singers, especially the prima donna".William Ashbrook has speculated on this last point that Eckerlin may have been chafing at the restrictions of her contract, as by this time she had already appeared with some success at La Scala, where she had debuted in La gazza ladra during the 1817–18 season.