Leif Dietrichson (1 September 1890 – disappeared 18 June 1928) was a Norwegian military officer and aviation pioneer.

He was a cousin of Bernt Balchen, and nephew of Oluf Christian Dietrichson, who had been with the Fridtjof Nansen expedition to Greenland (1888–89).

[5] Dietrichson participated in Roald Amundsen's North Pole expedition in 1925, which reached 87° 43' N.On 21 1925 May two Dornier Wal aircraft boats, N-24 and N-25, took off from Ny-Ålesund on the island of Spitsbergen.

N 25 was led by Hjalmar Riiser-Larsen, with Roald Amundsen as a navigator and Karl Feucht as a mechanic.

After 7 hours of flight, the expedition made an emergency landing due to motor difficulties.