Archibald Fenner Brockway was born in Calcutta, India, 1 November 1888, the son of W. G. Brockway and Frances Elizabeth Abbey. He was educated at Eltham College. He married Lilla Harvey-Smith in 1914 (divorced 1945), with whom he had four daughters, and Edith Violet King in 1946 (separated 1982), with whom he had one son.

He campaigned on behalf of the Liberal Party in parliamentary and local elections and was active in the Women's Suffrage movement. Later he joined the Independent Labour Party (ILP). He worked on the staff of the "Examiner", 1907-9, as a sub-editor on the "Christian Commonwealth", 1909-11 and as a sub-editor, 1911, and editor, 1912-17, on the "Labour Leader", the ILP weekly. He was Secretary of the No Conscription Fellowship, 1917, and served four terms of imprisonment as a conscientious objector during the First World War, 1916-19. He was Joint Secretary of the British Committee of Indian National Congress and editor of "India", 1919, and Joint Secretary of the Prison System Enquiry Committee, 1920.

Brockway was an active member of the ILP, serving as: Organising Secretary, 1922; General Secretary, 1928 and 1933-9; Chairman, 1931-3; and Political Secretary, 1939-46, also editing "New Leader", 1926-9 and 1931-46. He also organised an ILP contingent to fight with the Republican forces during the Spanish Civil War, 1936-9. He served as MP for East Leyton, 1929-31 and joined the Labour Party in 1946, being elected as MP for Eton and Slough, 1950-64. He campaigned for racial equality, introducing a bill outlawing racial discrimination for nine successive years before legislation was passed in 1964. He was created a life peer, as Lord Brockway of Eton and Slough, 1964, and continued an active political career in the House of Lords.

Brockway was a lifelong anti-colonialist and peace campaigner. He travelled extensively in India between the wars and in Africa during the 1950s and 1960s. He helped to establish the People's Congress Against Imperialism, 1948, was a founder and Chairman of Liberation (formerly the Movement for Colonial Freedom), 1954-67, a leading light of the Campaign for Nuclear Disarmament, and a founder, with Philip Noel-Baker, of the World Disarmament Campaign, 1979.

He died on 28 April 1988. He is commemorated by a statue in Red Lion Square, London.

His publications include: "The Devil's Business" (1915); "Non Co-operation in Other Lands" (1921); "India and its Government" (1921); with Stephen Hobhouse "English Prisons Today" (1922); "A New Way with Crime" (1928); "The Indian Crisis" (1930); "Hungry England" (1932); "The Bloody Traffic" (1933); "Will Roosevelt Succeed?" (1934); "Purple Plague" (1935); "Workers' Front (1938); "Inside the Left" (1942); with Frederic Mullally, "Death Pays a Dividend" (1944); "German Diary" (1946); "Socialism Over Sixty Years: the life of Jowett of Bradford" (1946); "Bermondsey Story: life of Alfred Salter" (1949); "Why Mau Mau?" (1953); "African Journeys" (1955); "1960 - Africa's Year of Destiny" (1950); "Red Liner" (1961); "Outside the Right" (1963); "African Socialism" (1964); with Norman Pannell, "Immigration: what is the answer?" (1965); with [Cora] Wendy Campbell-Purdie, "Woman Against the Desert" (1967); "This Shrinking Explosive World" (1968); "The Next Step to Peace" (1970); "The Colonial Revolution" (1973); "Towards Tomorrow" (1977); "Britain's First Socialists" (1980); and "98 Not Out" (1986).