Nadine Sierra (born May 14, 1988) is an American operatic soprano. On February 21, 2009, she won the Metropolitan Opera National Council Auditions Finals in New York.
A native of Fort Lauderdale, Florida, she trained at The Mannes College of Music and Marilyn Horne's Music Academy of the West, where she was the youngest person ever to receive the Marilyn Horne Foundation Award. She became a Young Artist with the Palm Beach Opera when she was 14 and made her operatic debut there two years later as the Sandman in Engelbert Humperdinck's Hansel and Gretel. She also appeared on the National Public Radio program From the Top when she was 15 performing "O mio babbino caro" from Gianni Schicchi.
She was invited back to From the Top in 2010, a show taped in Burlington, Vermont, with commentary by Marilyn Horne. She appeared at the United States Supreme Court Building in May 2009 where she sang solo and with Thomas Hampson in the Justices Chambers. In 2009 she competed in Helsinki, Finland, in the Mirjam Helin International Competition where she was awarded second place. She had her debut concert in Helsinki, Finland in 2009. In October 2009 she performed in the Marilyn Horne Mediterranean Cruise to Italy, Croatia, Turkey and Greece. In March 2010 she performed at the Musashino Hall, Tokyo, Japan.