Andresen

Andresen is a patronymic surname of North Germanic origin, most common in Denmark and Norway. It is derived from the given name Andreas (the equivalent of Andrew) and the old Danish‑Norwegian suffix -en, indicating "son of Andreas." The form is part of a broader family of Andreas-derived surnames, including Andersen, Andersson, and Andersen, which share the same root but reflect different linguistic traditions and spelling conventions.

In Denmark and Norway, Andresen has been established as a surname since the late Middle Ages, and it became widespread through migration and the standardization of naming practices in the early modern period. In Germany and among German-speaking communities, the surname occurs as well, likely through historical contact and movement across borders; in some lines, Andresen may have originated as a patronymic rather than a fixed family name.

Today, Andresen is found in Nordic countries and in emigrant communities around the world, including North America. The spelling varies by country and family line, with -sen forms generally associated with Danish and Norwegian usage, and -sson or -son forms more common in other Nordic regions; overlaps occur where families migrated and adapted their names.

Notable bearers span various fields, reflecting its broad dispersion, and related surnames such as Andersen and Andersen-type variants are treated as cognates in genealogical sources. See also Andersen, Andres, and Andreson for related names.