Adele Marcus (February 22, 1906 – May 3, 1995) was an American pianist and instructor.
Marcus was born in Kansas City, Missouri, the youngest of 13 children of a rabbi of Russian descent. She studied under Josef Lhévinne and Artur Schnabel. After winning the Walter W. Naumburg Foundation Award in 1928, she made a series of solo recital debuts in Chicago, San Francisco and New York City. Of her New York debut in 1929, the New York Times wrote: "Last night she displayed distinguished gifts both as a technician and an interpreter."
She was on faculty at the Juilliard School in New York City from 1954 to 1990 and provided master classes in piano performance at other conservatories including the American Conservatory of Music in Chicago during the 1970s in collaboration with William Browning, also a teacher of great repute.
Marcus's performances included a Carnegie Hall recital on January 25, 1949, in which she played Scarlatti, Brahms, Schubert, Schumann, Scriabin, Rachmaninoff, Stravinsky and Chopin. Her students included: Edward Aldwell, Agustin Anievas, Tzimon Barto, Jeffrey Biegel, Enrique Bátiz, David Brunell, Anthony Byrne, Sergio Calligaris, José Carlos Cocarelli, Cy Coleman, Stewart L. Gordon, Steven Graff, Horacio Gutiérrez, Stephen Hough, Byron Janis, Soonja Kim, Daniel Lessner, Panayis Lyras, Diana McIntosh, Beata Moon, Pascal Nemirovski, Ken Noda, Jon Kimura Parker, Santiago Rodriguez, Neil Sedaka, Jeffrey Swann, Emma Tahmizian, and Ezequiel Viñao.