Jan Birger Jansen (25 September 1898 – 24 November 1984) was a Norwegian physician, anatomist and scientist, specializing in brain research.
He was born in Horten as a son of captain James Christian Jansen (1868–1912) and Ananda Kristine Jacobsen (1874–1961).
He was hired as a prosector there in 1926, studied with a Rockefeller Grant under C. Judson Herrick at the University of Chicago from 1927 to 1929, and back in Norway he took the dr.med.
[2] He edited the illegal newspaper Bulletinen from 1941; from 1942 to 1944 as the sole editor,[1][3] and was a member of the so-called Coordination Committee (Norwegian: Koordinasjonskomiteen (KK)).
[1] In 1961 Jansen stood forward as a member of Landsforbundet for folkeavstemning, a lobby organization which worked to include the institution of referendums in the Norwegian Constitution.