Karl Ludvig "Kalle" Reichelt (28 November 1933 – 29 October 2016) was a Norwegian medical researcher.
In 1972, he delivered his PhD thesis at the University of Oslo: “An investigation into the nature and function of anionic acids, peptides, and acid-soluble proteins from brain tissue”.
The voluntary association Mat og Atferd (in English Food & Behaviour) is established in Norway on the basis of Reichelt´s work.
He worked daily at Rikshospitalet, Norwegian for the National Hospital, in Oslo, Norway, until medio 2012 as a senior researcher and advisor.
Karl Ludvig Reichelt received HM The King's Medal of Merit in gold in 2004.