Born Olga Maria Elisabeth Frederike Schwarzkopf in Jarocin, Poland, Schwarzkopf showed an interest in music from the very beginning. She performed in her first opera in 1928, as Eurydice in a school production of Orfeo ed Euridice in Magdeburg, Germany.
In 1934, Schwarzkopf began studying at the Berlin Hochschule für Musik, initially as a mezzo-soprano, later as a coloratura soprano.
Schwarzkopf made her professional debut at Berlin's Deutsche Oper on April 15, 1938 as the Second Flower Maiden (First Group) in Act II of Wagner's Parsifal. She sang at the Deutsche Oper for four years, during which time she became a member of the Nazi Party (a controversial decision which caused her to be boycotted in the United States after the war).
She left the Deutsche Oper in 1946 and joined the Theater an der Wien in Vienna, where her roles included Mimi in La Bohème and Violetta in La Traviata.
When the Vienna State Opera went on tour from 1947 to 1948, Schwarzkopf joined them and was able to travel to Europe's leading opera houses. With the Vienna company, she performed at London's Royal Opera House at Covent Garden on 16 September 1947 as Donna Elvira and at La Scala on 28 December 1948 as the Marschallin. She later made her official debut at Royal Opera House on 16 January 1948 as Pamina in Die Zauberflöte and at La Scala on 29 June 1950 singing Beethoven's Missa Solemnis.
On 11 September 1951, she appeared as Anne Trulove in the world premiere of Stravinsky's The Rake's Progress.
Schwarzkopf made her debut at the Metropolitan Opera on October 13, 1964, as the Marschallin.
In March 1946, Schwarzkopf was invited to audition for Walter Legge, a classical music producer. She sang Wolf's Lied "Wer rief dich denn?" and Legge signed her to an exclusive contract with EMI. They began a close partnership and Legge became Schwarzkopf's manager and companion. They were married on October 19, 1953, in Epsom, England.
In the 1960s, Schwarzkopf concentrated nearly exclusively on five five operatic roles, Donna Elvira Countess Almaviva, Fiordiligi, Countess Madeleine in Capriccio, and, probably her most famous role, the Marschallin in Der Rosenkavalier. She also was well received as Alice Ford in Falstaff.
Schwarzkopf's last operatic performance was as the Marschallin on December 31, 1971 in Brussels. For the next several years, she devoted herself exclusively to lieder recitals. On March 17, 1979, Legge suffered a severe heart attack. He disregarded doctor's orders to rest and attended Schwarzkopf's final recital on the 19th in Zürich. Three days later, Legge died.
Since retiring, Schwarzkopf has been teaching and giving masterclasses. She lives in Zürich.
During her career, Schwarzkopf was much admired for her timeless beauty, but some critics found her mannered singing and coquettish acting tiresome.