politician member of the Parliament of Norway
He was elected to the Norwegian Parliament from the Market towns of Sør-Trøndelag and Nord-Trøndelag counties in 1945, and was re-elected on six occasions. From 1969 to 1973 he was President of the Odelsting. He was chairman of Arbeidernes Ungdomslag in Trondheim from 1932 to 1935, and of the county chapter of the Workers" Youth League from 1937 to 1938.
Johnsen was a member of Trondheim city council in 1937–1940, 1945–1947, 1947–1951 and 1951–1955.