Birgit Nilsson (Marta Birgit Svensson) (b. May 17, 1918) is a Swedish soprano. She was born in Västra Karup, Skåne County, Sweden.

In 1947 she gained national attention as Lady Macbeth in Verdi's Macbeth at the Royal Swedish Opera. In 1959 she gained North American prominence as Isolde in Wagner's Tristan and Isolde at the Metropolitan Opera in New York City.

She has performed at many major opera venues in the world including Tokyo, Paris, Buenos Aires, Chicago, San Francisco, and Hamburg.

The American Scandinavian Foundation has named their prize for promising young American opera singers the Birgit Nilsson Prize.