Swedish singer, known for her soprano roles, especially in the operas of Wagner and Richard Strauss.
Nilsson entered the Royal Academy of Music, Stockholm, in 1941, where she studied with Joseph Hislop. Her debut (1946), at the Stockholm Royal Opera in the role of Agathe in Weber's Der Freischütz, was as a last-minute replacement. Five years later she had her first success outside Sweden, as Electra in Mozart's Idomeneo at Glyndebourne. By 1955 Nilsson had established herself as a world-class singer, making her US debut in San Francisco (1956) and singing Wagner's Isolde at the Metropolitan Opera, New York, in 1959. She was also well known for her interpretation of Leonora in Beethoven's Fidelio. She retired in 1982.