Sara Caldwell was educated at the University of Arkansas Hendrix College and at the New England Conservatory, where she studied the violin under Richard Burgin.  In 1946, she won a scholarship as a viola player at Tanglewood, where the next year she staged Vaughan Williams' Riders to the Sea.  She then studied with Boris Goldovsky.  From 1952 to 1960, she was head of the Boston University opera workshop; in 1957, she founded what was to become the Opera Company of Boston.

She established herself as a conductor and as an innovatory producer of a wide range of operas in Boston and, subsequently, throughout the USA, and has given the American premieres of such works as Prokofiev's War and Peace, Luigi Nono's Intolleranza, Schoenberg's Moses und Aron, and Roger Sessions' Montezuma.  In 1976, she became the first woman conductor of the Metropolitan Opera.  She is also and orchestral conductor, and has appeared with the New York PO, the Pittsburgh SO, and the Boston SO.  She has always been known for her interest in staging difficult and demanding works under adverse conditions, and enjoys producing variant editions of standard works.  As a producer, she is considered a follower of Walter Felsentein, but in fact her approach to each opera is wholly her own; and she is to be regarded as one of the most influential opera producers in the USA.