What does the last name anderson mean?

the origin of the last name Andersons. Patronymic surname meaning "son of Andrew." Andrew (man, manly) was the first of Jesus' disciples, and was a revered name in medieval times due to its church connections. St. Andrew is the patron saint of both Scotland and Russia.

Swedish patronymic "son" names traditionally end in -son, not -sen. In Denmark the regular patronymic is -sen. In Norway, both are used, although -sen is more common. Icelandic names traditionally end in -son or -dotir.