[3] The young Astrup was educated at the private Gjertsen School in Kristiania, before embarking on his philological and mercantile studies in England and Belgium.

[6][5] Representing the Oslo Conservative Party, Astrup was elected to the Parliament of Norway in 1924; he sat through one term.

Astrup also had positions in parliamentary committees, in Statens metalsentral (1918–1920) and in boards of Norwegian corporations.

[5] He chaired Standards Norway from 1924 to 1934 and Christiania Søforsikringsselskab from 1932 to 1944,[1] as well as Norsk Spisevognselskap, Grubernes Sprængstoffabriker and Dalen Portland.

[4][5] He was a board member of Norges Handels- og Sjøfartstidende from 1917 to 1933, Den norske Creditbank from 1928 to 1944 (deputy chairman since 1932), Storebrand and Idun from 1931 to 1946,[1] as well as Elektrokemisk.