Gaby Casadesus (1901-1999) was a French classical pianist and teacher born in Marseilles, France. She was married to the famous French pianist Robert Casadesus, and their son Jean Casadesus was also a notable pianist.
Originally Gaby L'Hote, she entered the Paris Conservatoire when she was 12, and became a student of Marguerite Long and Louis Diemer. She graduated from the Conservatoire with a first prize in piano when she was 16 and soon established herself with performances of Faure, Ravel and Milhaud, which she studied with the composers' guidance.
Her recitals also reached further back into the French keyboard literature to include music of Rameau, Couperin and Chopin. She was known as an elegant Mozart interpreter, and in 1923 was awarded the Prix Pages, recognized as the highest achievement for female pianists in France.
When she was still at the Conservatoire she met Robert Casadesus, her husband. They began giving performances of duo piano works together. Robert Casadesus wrote several works for the duo, including Six Pieces (1938), and a Concerto for Two Pianos, which they performed with the New York Philharmonic in 1950.
In the 1960's their son Jean Michel Casadesus sometimes joined them for performances of the Bach Triple Concerto and Robert Casadesus's Concerto for Three Pianos. However, this all ended when Jean Michel Casadesus died in an automobile accident in January 1972. Her husband Robert died soon thereafter. During World War II the Casadesus family settled in Princeton but returned to France in 1946. Both were influential teachers at the American Conservatory at Fontainebleau, France. Mrs. Casadesus also gave regular master classes at the Salzburg Mozarteum and at several French and American universities. She was the author of two books, ''Ma Technique Quotidienne'' (''My Daily Technique,'' written with Philip Lasser, one of her students) and ''Mes Noces Musicales'' (''My Musical Wedding,'' written with J. Muller).
After her husband's death she helped found an annual summer festival in Lille, France, with her nephew, the conductor Jean-Claude Casadesus, and in 1975 she started the Robert Casadesus International Piano Competition, in Cleveland. She devoted herself to performing and publishing her husband's compositions until her own death in 1999.