Fanny Heldy (29 February 1888 - 13 December 1973) was a lyric soprano opera singer. Born Marguerite Virginie Emma Clémentine Deceuninck in Ath (some sources say Liège), Hainaut, Belgium. She graduated from the Liège Conservatoire. Heldy made her professional debut as a substitute in the premiere of Ivan the Terrible, by Raoul Gunsbourg (at the La Monnaie, 26 November 1910). Between 1914 and 1918 she sang a number of major roles at Opéra de Monte-Carlo, making her first Paris appearance at the Opéra-Comique in 1917 as Violetta in La traviata. She portrayed Juliette in Charles Gounod's Roméo et Juliette at the Paris Opéra in 1920.