Look up Karlsson in Wiktionary, the free dictionary.
Karlsson is a Scandinavian patronymic surname meaning "son of Karl" or "Karl's son". It is one of the most common surnames in Sweden and has a number of alternative spellings. Apart from Karlsson, Carlsson is the most common spelling variation. Karlson and Carlson also exist, but are uncommon, as are Carlzon and Qarlsson (Annika Qarlsson). The parallel Danish-Norwegian forms are Karlsen and Carlsen.
The surname is also found in Iceland, where it is not strictly a surname, but a patronymic.