Nilsen is a Norwegian patronymic surname meaning "son of Nils". The given name Nils is itself a Scandinavian form of Nicholas, which ultimately derives from the Greek Νικόλαος (Nikolaos), composed of nike meaning "victory" and laos meaning "people". Thus, the name carries the deeper meaning of "victory of the people" through its etymological roots.History and DistributionAs a patronymic surname, Nilsen follows the common Scandinavian naming tradition where the suffix -sen (or -son) indicates "son of". Thus, Nilsen literally denotes "son of Nils". This tradition was especially prevalent in Norway, where fixed hereditary surnames became common only in the 19th and early 20th centuries. The name Nilsen is among the most frequent surnames in Norway, ranking as the 4th most common by some counts, reflecting the popularity of the patronymic naming system.Notable BearersThe Wikipedia article lists many notable individuals bearing this surname, spanning diverse fields:Dennis Nilsen (1945–2018), a British serial killer whose notoriety has made the name widely known in true crime circles.Adolf Nilsen (1895–1927), an Olympic rower from Norway who competed in the 1920 Summer Games.Elin Nilsen (born 1968), a Norwegian cross-country skier who won Olympic medals.Achintya Holte Nilsen (born 1999), an Indonesian-Norwegian model and activist.B. J. Nilsen (born 1975), a Swedish sound artist.Additionally, the list includes Norwegian politicians such as Alfred Nilsen, Arne Nilsen, and others.Related SurnamesVariants of Nilsen exist in other languages and cultures, all ultimately derived from the name Nicholas. In English, the equivalent Nelson is common, meaning "son of Nel" (a medieval diminutive of Nicholas). Other cognates include the Russian Nikolaev and Nikolaeva, the Macedonian Nikolov and Nikolova, the Serbian Nikolić, and the Slovak Mikula. All these surnames mean "son of Nicholas" or similar, but with language-specific suffixes.