Born on Christmas Eve 1927 in New Hartford, Connecticut, Stich-Randall studied at the Hartt School of Music in Hartford and at Columbia University in New York. She made her operatic debut before she was 20, as Teresa Stich, in the 1947 world premiere of Virgil Thomson's The Mother of Us All; the following year she created the title role in Otto Luening's Evangeline. She was then discovered by Arturo Toscanini, who called her "the find of the century" and engaged her for a series of performances with his NBC Symphony.

In 1951 Stich-Randall won the Lausanne Competition in Switzerland and began her European career; by the next year she had made a debut at the Vienna State Opera, where she would perform regularly for the two decades. (In 1963 the house conferred on her the honorary title of Kammers‹ngerin; she was the first American to be so honored.)

Stich-Randall went on to perform, in opera and concert, at the Salzburg Festival (1952-60), La Scala, the opera houses of Genoa, Turin and Naples, and widely in germany and Switzerland. She had a long association with the Aix-en-Provence Festival, where she sang every year from 1953 to 1972, notably in a cycle of Mozart operas under conductor Hans Rosbaud.

Her American career seems to have been relatively brief. She made a Lyric Opera of Chicago debut in 1955 as Gilda in Verdi's Rigoletto; she first appeared at the Metropolitan Opera in 1961, as Fiordiligi in CosÐ fan tutte and later sang Donna Anna in Don Giovanni, remaining on the roster until 1966.

She wound her career down during the 1970s and had retired from the stage entirely by 1980, but for two brief return visits to her hometown in 1982 and 1983. She did continue to teach master classes, according to the Courant.

Among Stich-Randall's notable recorded performances, in addition to the Rosbaud Mozart cycle from Aix, are Nanetta in Verdi's Falstaff under Toscanini, Sophie in Strauss's Der Rosenkavalier under Herbert von Karajan (opposite Elisabeth Schwarzkopf and Christa Ludwig), Euridice in Gluck's Orfeo under Charles Mackerras (opposite Maureen Forrester), and a series of Bach cantatas with conductors Felix Prohaska and Karl Ristenpart, in particular a Jauchzet Gott in allen landen (BWV 51) with Maurice Andr_ playing the trumpet solos.

Her singing, by no means to every opera lover's taste, was marked by light tone and accurate pitch with minimal vibrato; she could thus be seen as a forerunner of the period-performance movement exemplified (among singers) by Emma Kirkby. One might even suggest that Stich-Randall was born about 20 years too early.