Nina Maria Stemme (born Nina Maria Thöldte on May 11, 1963) is a Swedish dramatic soprano opera singer.
Stemme "is regarded by today's opera fans as our era's greatest Wagnerian soprano". In 2010, Michael Kimmelman wrote of one of Stemme's performances in Richard Wagner's opera Die Walküre, "As for Brünnhilde, Nina Stemme sang gloriously. It's hard to recall anyone's sounding more commanding or at ease in the part, and that includes Kirsten Flagstad".
Born in Stockholm, the young Stemme played piano and viola. She attended Adolf Fredrik's Music School (Swedish: Adolf Fredriks Musikklasser), a high-profile song-and-chorus school in Stockholm. During a year as an exchange student at Langley High School in McLean, Virginia, she joined the school chorus, sang solos and won awards.
Parallel to her studies of business administration and economics at the , Stemme followed a two-year course at the Stockholm Operastudio. Her debut as Cherubino in Cortona, Italy, in 1989 made Stemme decide to follow a professional singer's career; her studies at the in Stockholm were completed in 1994. In addition to two minor roles at the Royal Swedish Opera in Stockholm, she also sang Rosalinde (Die Fledermaus), Mimì (La bohème), Euridice in Gluck's Orfeo ed Euridice, and Diana (La fedeltà premiata by Haydn).
She sang in two singing competitions, Operalia, The World Opera Competition and Cardiff Singer of the World. As winner of Operalia in 1993, Stemme was invited by Plácido Domingo, founder of Operalia, to appear with him in a concert at La Bastille (1993); the same concert also took place on January 1, 1994, in Munich.