Sylvia was found by N. R. Pogson on May 16, 1866 from Madras (Chennai), India. Paul Herget, in his "The Names of the Minor Planets" (1955), attributes the name as honouring the first wife of astronomer Camille Flammarion, Sylvie Petiaux-Hugo Flammarion (this entry is signed by A. Paluzie-Borrell). However, in the article announcing the discovery of this asteroid ("MNRAS", 1866), Pogson explained that he selected the name in reference to Rhea Silvia, mother of Romulus and Remus.