American-born Greek operatic soprano who revived classical coloratura roles in the mid-20th century with her lyrical and dramatic versatility.

Callas was the daughter of Greek immigrants and early developed an interest in singing. Accompanied by her mother, she left the United States in 1937 to study at the Athens Conservatory with soprano Elvira de Hidalgo; in 1966 she became a Greek citizen and relinquished her U.S. citizenship. She sang locally in Cavalleria rusticana and Boccaccio and returned to the United States in 1945.

Her career began in earnest in August 1947, when she appeared in Verona in La gioconda. Soon, under the tutoring of conductor Tullio Serafin, she made debuts in Venice, Turin, and Florence. In 1949 she first appeared in Rome, Buenos Aires, and Naples, and in 1950 in Mexico City. Her powerful soprano voice, capable of sustaining both lyric and coloratura roles, was, although not perfect in control, intensely dramatic; combined with her strong sense of theatre and her scrupulously high artistic standards, it took her quickly to the forefront of contemporary opera stars. Her talents made possible the revival of 19th-century bel canto works, notably those of Bellini and Donizetti, that had long been dropped from standard repertoires.

Callas made her debut at the prestigious La Scala in Milan in 1950, singing in I Vespri siciliani. In 1952 she appeared at Covent Garden, London. Her American debut took place in November 1954 at Chicago's Lyric Opera in the title role of Norma, a performance she repeated before a record audience at the Metropolitan Opera in New York City. Callas's recordings were enthusiastically received, and she was one of the most popular singers of the period. Her much-publicized volatile temperament resulted in several protracted feuds with rivals and managers.

After a final operatic performance as Tosca at Covent Garden (July 1965), Callas made the film Medea (1971) and taught master classes in opera at Juilliard (1972) before a last U.S. and European concert tour (1973–74). By the time of her retirement, she had performed more than 40 different roles and had recorded more than 20 complete operas