Njål Sparbo studied singing with Jan Sødal, Aase Nordmo Løvberg, Ingrid Bjoner and Tor Hommeren in Norway. He has attended Master Classes with Hans Hotter, Dietrich Fischer-Dieskau, Kurt Moll, Jorma Hynninen, Thomas Hemsley, Edith Mathis, Galina Vishnevskaya and Oren Brown. Following his official debut concert in 1991, he has distinguished himself as one of Norway's most active and versatile singers with an exceptionally broad repertoire spanning from art song, sacred music to opera. His special interest in contemporary music has led to many commissions, numerous world premieres, stage productions and recordings.

He has been a soloist with all the major Norwegian choirs, orchestras, and the Norwegian National Opera. He has given numerous performances throughout Europe, Russia, Japan, South-Korea, and the United States. In Norway he has given more than 150 recitals together with the nation’s leading pianists and has regularly appeared at festivals, in operas, and in radio and television. His discography comprises 32 recordings, including the first two recordings of a CD-anthology of Norwegian songs, “Norge, mitt Norge!”, and “Natt og Dag”.

Sparbo has been awarded numerous awards and scholarships, among others from the Wallenberg stipend fund, Klæstad's endowment, Fegersten's endowment, Ingrid Bjoner's scholarship and the Kirsten Flagstad Prize. After performing all the songs by Edvard Grieg in concerts, he received the Grieg Prize in 2009 for his contributions to "renew the musical interpretation tradition in Grieg's songs, particularly by bringing up the dramatic scope".

Sparbo received the Norwegian Government Grant for Artists for two periods, 1997-1999 and 2005-2008, to study Norwegian, German and Russian art song repertoire. In 2009-2014 he worked as a research fellow at the Oslo National Academy of the Arts in the Norwegian Artistic Research Fellowship Programme. His project «Singing on the Stage - with a Psychophysical Approach» merged different aspects of artistic performance practice (Konstantin Stanislavski, Roy Hart, Rudolf Laban, Jacques Lecoq) with the Norwegian psychomotor tradition (Trygve Braatøy, Berit Heir Bunkan). In 2014-15 he joined the research group "The Reflective Musician – Interpretation as co-creative process" at the Norwegian Academy of Music. In 2017-20 he was part of the artistic research group "(Un-) settling Sites and Styles - in Search of New Expressive Means" at the University of Bergen with the sub-project “Sonotical Interpretations of 70 Songs by Geirr Tveitt”.

His research of psychophysical stage presence, combining contemporary aesthetics with concepts from Norwegian psychomotor physiotherapy led to educational engagements as associate professor at the Opera and Ballet Academies within the Oslo National Academy of the Arts, the University in Bergen. He has given several Master Classes in Norway, in the Netherlands and USA. In addition to coaching singers, he teaches vocal ensembles and choirs.

Sparbo has conducted peer reviews at the Norwegian Academy of Music, The Norwegian University of Science and Technology, and the University College of Opera in Stockholm. He has been managing director of Oslo Grieg Society and festival director of the Oslo Grieg Festival. In addition, he has been a member of the board for the Norwegian Operatic Association, the Artists' Union Scholarship Committee, and the International Edvard Grieg Society. As an entrepreneur, he founded the company Quattro Arts and Music in 1992, producing recordings, sheet music, design and websites for artists, art installations and live events.