| Knud Knudsen | |
| Birth Date: | 3 January 1832 |
| Birth Place: | Odda, Norway |
| Death Place: | Norway |
| Nationality: | Norwegian |
Knud Knudsen (3 January 1832 – 21 May 1915) was one of Norway's first professional photographers and a pioneer within Norwegian photography. His work includes images from most of Norway in his time and documents much of Norwegian history and ethnology in his photography career 1862–1900.
Knudsen was born in Odda, the son of a merchant who was also a pomologist. His professional career started as a retail clerk in Bergen, and in 1862 he traveled to Reutlingen to study pomology. He returned with an enthusiasm for photography the year after and opened his photography business in Bergen 1864.
Knud Knudsen left a collection of 13.500 wet and dry plate negatives, and about 20.000 of albumin silver prints. The negative and print collection are at The Picture Collection, University of Bergen Library.