La Source is a ballet made on New York City Ballet by its founding balletmaster (and co-founder) George Balanchine. The premiere took place on November 23, 1968, at the New York State Theater, Lincoln Center.
Balanchine's had previously made a "pas de deux" to music from Léo Delibes' "Sylvia" in 1950; he expanded this into a divertissement in 1965. The final version uses music from Delibes' ballets "La source" and "Sylvia" and choreography from the earlier pas de deux and divertissement.