Thomsen

Thomsen is a surname of Danish and Norwegian origin. It is a patronymic derived from the given name Thomas, meaning "son of Thomas." The given name Thomas ultimately derives from a Hebrew/Aramaic form that is commonly rendered as "twin" in popular etymology. In Nordic naming practice, the suffix -sen signals "son," so Thomsen identifies an ancestral line tied to a man named Thomas.

In Denmark and Norway, Thomsen is a common family name, often spelled Thomsen or Thomsson in some Norwegian or Icelandic-influenced contexts. Variants include Thomassen and Thomasson, as well as English-language cognates such as Thomason or Thomson. The distribution reflects historical migration between the Nordic countries and emigration to North America and elsewhere.

Notable people with the surname Thomsen have appeared across fields such as science, politics, sports, and the arts. Because of its patronymic origin, many unrelated families have adopted Thomsen independently in different regions.

See also: Thomson, Thomassen, Thomason. The surname is sometimes confused with related forms and with given-name uses in some contexts, but Thomsen remains a distinct Nordic surname.