Leif Juster (born Leif Normann Nilsen) (14 February 1910 – 25 November 1995) was a Norwegian comedian, singer and actor, arguably the most popular of his generation in Norway.

Juster started out as a variety show performer, and for a period he ran the theater Edderkoppen.

Characterised by his unusually tall, lanky figure and squeeky voice, his signature act was the monologue "Mot normalt".

[1] He also acted in several successful comedies on the big screen, notably Den forsvundne pølsemaker (1941), Det æ'kke te å tru (1942), En herre med bart (1942) and Fjols til fjells (1957).

He was the uncle of another of Norway's most beloved comedians, the late Rolf Just Nilsen.