The Norwegian Astronomical Society is a Norwegian organization active in astronomy research, education and outreach. The Society was founded in 1938 in Oslo initiated by Svein Rosseland, the professor who also founded the Institute of Theoretical Astrophysics at University of Oslo. Its members are both professional and amateur astronomers. The organization have almost two thousands members from the whole of Norway and is one of the oldest and most important amateur astronomical associations in Europe. During the 2004 Venus transit, NAS organized the Norwegian public show. It organizes national conferences and the Norwegian Astronomy Olympiad.
The society have several observation groups for meteors, comets, variable stars, supernova, occultations, sun, aurora. A shift towards a more professional orientation was formalized in 1968 when the journal «Astronomisk Tidskrift» (Astronomical Journal) was started as a joint venture of the Danish, Norwegian and Swedish societies. Since 1990, the journal «Astronomi» have been the official magazine for members.