Martin Tranmæl grew up on a middle-sized farm in Melhus Municipality, in Søndre Trondhjem county, Norway.

In the early 20th century, Tranmæl lived for a while in the United States where he came into contact with the American workers movement, and even though he joined the AFL, he was also present at the founding congress of the Industrial Workers of the World, whose revolutionary syndicalist ideology he continued to be influenced by after returning to Norway.

Eventually Tranmæl led the Norwegian Labour Party out of the Comintern after a conflict with its chairman Zinoviev in 1923.

He agitated for it through the newspaper Arbeiderbladet, and was convicted for this crime and sentenced to 5 months days of prison.

After the war he returned to Norway, and while still a socialist, had more moderate views and supported the Norwegian membership in NATO in 1949.