Andersen grew up in Harstad, where his father was a local master baker. In 1946 he acquired an 8 mm movie camera and started experimenting, and so to collect his first experience in this profession. Subsequently, he worked at various institutions and employers in the field of photography and film. From 1953 he was a director's assistant job at Norsk Film A / S and Star Film and from 1958 at Central Film, where he was initially involved only in production of advertising films. Subsequently, he then worked as an editor in the film section at several Norwegian film productions. In addition, he was later also a screenwriter and film director active. Outside the movies Anderson has been involved for the NRK and Lilly butikk also in several television productions such as 1994 Vestavind with 6 episodes. Knut Andersen was, together with the director Knut Bohwim and the cameraman Mattis Mathiesen of the founders of the Norwegian Film Society Team Film AS, which they founded together in 1962. Andersen and the Team Film Society revitalized in the 1960s, several Norwegian film comedies with large retail and box office hits, such as, among others, the films Operasjon Løvsprett and hurray for Andersen. Andersen also introduced in 1975 the director in the film Olsenbandens siste bedrifter from the 14 -part film series by the Norwegian Olsen Gang.
Andersen got 1976 Aamot -statuettes Film Award and on August 17, 2007 Amanda - prize at the opening of the movie norske festivalen in Haugesund.
Knut Andersen is married to theater director and film director Nicole Macé ( born May 17, 1931).