Leif Østby (2 January 1906 – 23 December 1988) was a Norwegian art historian.
His parents were Emil Augustinius Østby (1868-1937) and Klara Josefine Eeg (1870-1952).
From 1934-36, he was also engaged by Norsk Portrettarkiv, the department which collected and preserved photographs for the National Archives.
[2] [3][4] He published several works on the history of art and on individual artists, including Harald Sohlberg, Hjalmar Haalke, Johan Christian Dahl, Theodor Kittelsen and Erik Werenskiold.
Østby was a member of the Norwegian Academy of Sciences from 1956 and was awarded an honorary doctorate at the University of Oslo in 1986.