Sonja Hagemann (6 September 1898 – 17 October 1983) was a Norwegian literary historian and literary critic, especially of children's literature.
She is primarily known for the monumental Barnelitteratur i Norge (Norwegian Children's Literature I:1965; II:1970; III:1973).
She was raised in Christiania (now Oslo) Norway.
She graduated with a degree in economics at the University of Oslo (1919).
She first worked in government service.
She worked at Dagbladet as a critic of children's literature (1946-1971).
She received the Arts Council Norway Honorary Award (Norsk kulturråds ærespris) in 1980.
She represented the Liberal Party in Oslo school board.
She was a parliamentary ballot candidate from the constituency of Oslo in 1965.She was married to Otto Holmboe Hagemann (1891–1961) in 1925 and was the mother of geologist Fredrik Hagemann.