Fred Göran Karlsson (born February 17, 1946, in Turku) is a professor emeritus of general linguistics at the University of Helsinki.

[1] Fred Karlsson studied Finnish language at Åbo Akademi and phonetics at the University of Turku, and graduated in 1969.

[1] In computational linguistics Karlsson has designed a language-independent formalism called Constraint Grammar.

The basic original reference is Karlsson (1990) which defines Constraint Grammar.

Karlsson has also worked on the history of linguistics, where his main contribution is participation in a book by Even Hovdhaugen, Fred Karlsson, Carol Henriksen, and Bengt Sigurd, The History of Linguistics in the Nordic Countries, Societas Scientiarum Fennica, Jyväskylä 2000.