A native of Fort Lauderdale, Florida, she attended the Alexander W. Dreyfoos School of the Arts in West Palm Beach, Florida, and 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.
She appeared as the Princess with Gotham Chamber Opera's production of Xavier Montsalvatge's opera El gato con botas at the New Victory Theater. In January 2011 she returned to Palm Beach Opera's Orfeo ed Euridice in the title role. In May 2011 she appeared as Tytania in Boston Lyric Opera's A Midsummer Night's Dream. In January 2011 she became a San Francisco Opera Adler Fellow and the following May appeared in the company's premiere of Christopher Theofanidis' opera Heart of a Soldier with Thomas Hampson in the main role. In January 2012 she appeared as Gilda in Florida Grand Opera's Rigoletto.
Sierra is featured in the book Driven: Six Incredible Musical Journeys where author Nick Romeo dedicated one of the chapters ("Journeys") to her.
Sierra has been awarded the following awards and scholarships:
- National Foundation for Advancement in the Arts, Miami, Florida – Vocal Silver Award 2006
- Palm Beach Opera Vocal Competition, West Palm Beach, Florida – First Place Junior Division 2007
- The Marilyn Horne Foundation Awards Competition, Santa Barbara, California – First Place Award 2007
- National Society For Arts and Letters Vocal Competition, Bloomington, Indiana – Second Place Award 2008
- The Metropolitan Opera National Council Auditions, New York City – Grand Finalist Winner 2009
- Florida Grand Opera Competition, Miami, Florida – Junior Division First Place Award 2009
- Licia Albanese–Puccini International Competition, New York, NY – Third Place Award 2009
- Gerda Lissner Foundation Competition, New York City – First Place 2010
- Richard Tucker Foundation, New York City – 2010 Sara Tucker Study Award Winner
- George London Foundation Competition, New York City First Place 2010
- Loren Zachary Foundation International Competition, Los Angeles, California – First Place 2010
- The Leonore Annenberg Award Fellowship in the Performing Arts, 2011
- Stella Maris International Music Competition 2011, Audience Prize
- The Veronica Dunne International Singing Competition, Dublin, 2013
- Neue Stimmen, Gütersloh, Germany – 1st Prize and People's Choice Award 2013
- Metropolitan Opera, List of National Council Winners
- Stewart, Henry, "The Next Ones: Nadine Sierra (soprano)", The L Magazine, September 2, 2009
- Smith, Steve, "The On Wings of Song Series Shows a Fledgling's Flights", The New York Times, November 13, 2007
- Schultz, Alexandra, "Portrait of the Artists: Meet three unique talents defining the face of the South Florida cultural scene", Boca Raton Magazine, November 2008
- NPR From the Top, Green Room: Congratulations Met Council Auditions Winner Nadine Sierra
- "Adler Fellows Alumni". San Francisco Opera. Retrieved November 30, 2014.
- Romeo, Nick (2011). Driven: Six Incredible Musical Journeys, pp. 51–68. From the Top, Inc. ISBN 0-615-51140-6. See also Romeo, Nick (December 2009). "A Young Soprano's Journey to Victory at the Met". Classical Singer Magazine
- Ansa (January 1, 2016). "Concerto di Capodanno: alla Fenice si apre il 2016 in musica" (in Italian). quotidiano.net. Retrieved February 3, 2016.
- Eduardo Lamberti Castronuovo (January 13, 2016). "Scala, Leo Nucci (Rigoletto) e la giovane Nadine Sierra (Gilda) subissati di richieste di bis dal pubblico" (in Italian). video.corriere.it. Retrieved January 14, 2016.
- "Scala, pubblico in visibilio per la prima del Rigoletto. Concesso il bis chiesto a gran voce." (in Italian). rainews.it. January 14, 2016. Retrieved January 14, 2016.
- McCormick, Barbara (May 26, 2010). "National Society of Arts and letters hosts music fundraiser". Boca Raton Tribune
- Florida Grand Opera, Young Patronesses of the opera. Previous winners
- Licia Albanese–Puccini International Vocal Competition. 2009 winners; Photos
- Gerda Lissner Foundation. 2010 award winners
- Richard Tucker Foundation. Sara Tucker Study Grants 1998–2010
- George London Foundation (2010). Winners Circle[dead link]
- Wada, Karen (May 24, 2010). "Soprano Nadine Sierra wins top prize in national vocal competition". Los Angeles Times (Arts)
- Bertelsmann Stiftung, Gütersloh, Germany. "NEUE STIMMEN International Singing Competition - Competition". Retrieved 12 December 2015.