Andreassen is a common surname in Norway, meaning "son of Andreas". The parallel Danish forms are Andresen and Andreasen, the Swedish Andreasson. It may refer to:
Anita Andreassen, Norwegian mushing competitor; she has also competed in cycling and cross country skiing
Bjørn Andreassen (born 1946), Norwegian ice hockey player
Eivind Andreassen (born 1962), retired Norwegian football striker
Elisabeth Andreassen (born 1958), known as "Bettan", a Norwegian singer
Geir Hartly Andreassen, FSF, (born 1971), Norwegian cinematographer based in Stockholm, Sweden
Gunn Margit Andreassen (born 1973), Norwegian biathlete
Gunnar Andreassen (1913–2002), Norwegian football player and manager
Harald Magnus Andreassen (born 1956), Norwegian economist
Harriet Andreassen (1925–1997), Norwegian labour activist and politician for the Labour Party
John Andreassen (born 1943), Norwegian TV-producer with the Norwegian Broadcasting Corporation
Kenneth Andreassen (born 1985), Norwegian football midfielder
Kjell Schou-Andreassen (1940–1997), Norwegian footballer and one of the country's most successful football managers
Kristin Andreassen, American musician and dancer
Marit Andreassen (born 1966), Norwegian actress, born in Svolvær
Ole Petter Andreassen (born 1970), Norwegian musician and producer from Flekkefjord, Norway
Rolf Andreassen (born 1949), Norwegian competition rower and Olympic medalist
Rudolf Andreassen (1909–1983), Norwegian boxer who competed in the 1936 Summer Olympics
Tor Arne Andreassen (born 1983), Norwegian footballer who plays as a defender and midfielder
Tormod Andreasen, Norwegian curler
