Sjur Johnsen (20 June 1891 – 2 October 1978) was a Norwegian wrestler and track and field athlete.
Johnsen was born in Vik. He competed in wrestling at the 1920 Summer Olympics in Antwerp where he placed fourth in Greco-Roman middleweight, after losing the bronze match to Masa Perttilä. He was a national champion in 1920 and 1922.
Competing in track and field athletics, Johnsen won six national titles in hammer throw between 1923 and 1932.
Johnsen died in Bergen on 2 October 1978.