Niels Viggo Bentzon (Copenhagen, 24 August 1919 – Copenhagen, 25 April 2000) was a Danish composer and pianist.
Bentzon was descended from Johan Ernst Hartmann and the great-grandson of J.P.E. Hartmann. From 1938 to 1942, he studied at the Royal Danish Academy of Music in Copenhagen under Knud Jeppesen and Christian Christiansen. He then taught at The Royal Academy of Music in Aarhus (1945–50) and at The Royal Danish Academy (1950–88). His compositions extend to 664 opus numbers, including 24 symphonies, operas, ballets, concertos, string quartets, and many piano works. Arguably the most significant of these are the 14 separate sets of 24 preludes and fugues, collectively known as "The Tempered Piano", which represents a 20th-century example of music written in all 24 major and minor keys.
See List of compositions by Niels Viggo Bentzon