Bidu Sayão was born on 11 May 1902[1] to a family of Portuguese, French and Swiss heritage, in Itaguaí, Rio de Janeiro.

Her repertoire included Lucia di Lammermoor, Amina in La sonnambula, Elvira in I puritani, Zerbinetta in Ariadne auf Naxos and Cecilia in Il Guarany.

Her U.S. operatic debut followed on 21 January 1936 when she and Danise sang in the penultimate production of the Washington National Opera, a semi-professional company not associated with its modern namesake; the performance of Léo Delibes's Lakmé was marred by a fractious dispute in which the orchestra musicians declined to play without payment in cash, and ultimately the performance was accompanied by a portable organ, with some singers appearing in costume and some in street clothes owing to a similar demand by the stage hands and costume man.

[2] She performed a few months later with the New York Philharmonic at Carnegie Hall singing La Damoiselle élue by Debussy.

She sang her first performance at the Metropolitan Opera as Manon on 13 February 1937, replacing the Spanish soprano Lucrezia Bori.

She also contributed to the Mozart revival at the Metropolitan Opera, becoming the pre-eminent Zerlina (Don Giovanni) and Susanna (The Marriage of Figaro) of her generation.

Sayão's portrait by Curtis Ether hangs in the lobby of the Metropolitan Opera House in New York City.