Marie Constance Sasse [Sax, Saxe, Sass] (26 January 1834 – 8 November 1907) was a Belgian operatic soprano. "Her voice was powerful, flexible, and appealing",[1] and she was one of the leading sopranos at the Paris Opéra from 1860 to 1870. She created the roles of Elisabeth in the Paris premiere of Wagner's Tannhäuser, Sélika in the world premiere of Meyerbeer's L'Africaine, Elisabeth de Valois in the world premiere of Verdi's Don Carlos, and Cecilia in the world premiere of Gomes’ Il Guarany.[1]