Adèle Isaac (8 January 1854 – 22 October 1915) was a French operatic soprano, active in Paris in the late 19th century. Isaac was born in Calais. After studying with Gilbert Duprez, her professional debut was in 1870 in Victor Massé's Les noces de Jeannette at the Théatre Montmartre. In February 1873 she attracted attention singing the young shepherd in Tannhäuser at La Monnaie (Bruxelles). Her first performance at the Opéra-Comique was in 1873 as Marie in La fille du régiment, going on to sing Mozart and Gounod. On 3 April 1882 she sang Angèle in the 1,000th performance of Le Domino Noir at the Opéra-Comique.