Swinnerton left school at the age of 14 and was employed as an office boy for a newspaper publisher, Hay, Nisbet & Co and then as a clerk-receptionist by J. M. Dent, publishers of Everyman's Library. He moved on to the publishing house of Chatto & Windus, first as a proof-reader and then as an editor. Although he began writing novels in 1909, he continued editing until he became a full-time author in 1926. Even then, he also worked as literary critic for the magazine "Truth", the "London Evening News" (1929–32) and "The Observer" (1937-43).