John Sommerfield (25 June 1908 – 13 August 1991)[1] was a British writer and left-wing activist known for his influential novel May Day, which fictionalised a Communist upheaval in 1930s London.

Sommerfield's first two books, They Die Young (1930) – which was published in the United States as The Death of Christopher – and Behind the Scenes (1934) drew upon his experiences at sea and as a stage hand.

[3][4] Shortly after the publication of May Day, Sommerfield volunteered for the International Brigades, fighting in the Spanish Civil War alongside his friend John Cornford.

Malcolm Lowry, a close friend of Sommerfield's, counted him as an important influence, and dedicated his poem Song About Madrid, Useful Any Time to him and Julian Bell.

After the war, he lived with his second wife, the artist and illustrator Molly Moss, in Hampstead and Gospel Oak in north London before moving to Oxfordshire where he died in 1991.