Zilli was born in Fagagna, Udine. She was trained as a pianist and began singing only after her marriage to the painter Giacomo Zilli, in 1882. She made her stage debut in 1887 at Ferrara as Paolina in Donizetti's Poliuto and in 1889 first sang at La Scala, Milan, as Camille in Hérold's Zampa. In the same house she created the role of Alice Ford in Verdi's Falstaff (1893), and made her Covent Garden debut in the same role in the British premiere of the opera (1894).
- "Zilli, Emma. Soprano". Dizionario biografico dei personaggi citati a cura di Gaspare Nello Vetro (in Italian). Archived from the original on 2012-02-23.
- Busch, p. 212
- Forbes, Elizabeth. "Zilli, Emma", The New Grove Dictionary of Opera, ed Stanley Sadie, Grove Music Online, Oxford University Press, accessed 27 July 2013 (subscription required)
- Budden, p. 140; and "Royal Opera", The Times, 21 May 1894, p. 7