Hans Jacob Aall (20 September 1869 in Arendal – 6 November 1946 in Oslo) was a Norwegian librarian and museum director.

He was born in Arendal to ship owner Diderik Maria Aall and Marie Elisabeth Herlofson.

He was a great-grandson of Niels Aall, and nephew of Axel Nicolai Herlofson,[1] and a member of the Aall family which originates in Denmark (Aal Sogn) in the 1500s.

He was decorated Knight of the Order of St. Olav in 1909, and Commander in 1929.

This biographical article about a Norwegian academic is a stub.