Ivar Lo-Johansson (23 February 1901, Ösmo - 11 April 1990, Stockholm) was a Swedish writer of the proletarian school.

He described the situation of the Swedish land-workers, statare, in his novels, short stories and journalism, which encouraged the adoption of certain land reforms in Sweden. He also caused much controversy with his features on old-age pensioners, Gypsies and other non-privileged people.

Lo-Johansson is however best known for his vivid recollections of the life in Swedish trade-unionist and literary circles of the twenties, thirties and forties. He also continued throughout his long life to insist that literature should face the world from the under-dog's perspective.