Emil Diesen (14 April 1880 – 24 June 1942) was a Norwegian civil servant and editor.
He was born in Norderhov a son of captain Ernst Georg Diesen (1841–1908) and Anna Kathrine Fredrikke Elisabeth Seip (1851–1930).
His largest work was Norsk industri- og næringshaandbok, a registry of several branches of Norwegian industry and business.
There were also handbooks for the banking and insurance industries, and one volume covered the press and journalists in Norway at the time.
[5] He later issued several yearbooks of "exchange rates of the world", and his last books were about the banks of specific counties.