Born in Barbados, Braithwaite went to sea with the British merchant navy as a teenager and travelled the world as a sailor. He then settled in Chicago and founded a family, before rejoining the Merchant Navy during World War I. After World War I he lived in New York City for a while, before moving to settle in London, working for the Shipping Federation. He married a white woman, Edna, from Stepney, and they lived in Stepney.
Braithwaite became a member of the National Union of Seamen, and in 1930 joined the Seamen's Minority Movement, a rank-and-file group organised by the Communist Party of Great Britain (CPGB). Taking the pseudonym "Chris Jones" to avoid victimisation by his employer, Braithwaite had joined the CPGB by 1931. He helped distribute the Negro Worker, and with Arnold Ward helped launch the Negro Welfare Association, publicising the case of the Scottsboro Boys. In 1933 he followed George Padmore in resigning from the CPGB in protest at the implicit shift away from anti-imperialism involved with the emerging "Popular Front" strategy.
In 1935, opposing the new British Shipping (Assistance) Act 1935, Braithwaite founded the Colonial Seamen's Association - which included Asian seamen alongside other black colonial seamen. He became organising secretary of the International African Service Bureau (IASB), established in May 1937, whose members included Padmore, C. L. R. James, Jomo Kenyatta, Amy Ashwood Garvey and I. T. A. Wallace-Johnson. Braithwaite wrote a monthly column, "Seamen's Notes", for the IASB journal, International African Opinion. Braithwaite, Padmore and James continued to oppose the CPGB, turning up together to heckle CPGB meetings. Braithwaite and Padmore worked with the Independent Labour Party (ILP) and with ILP intellectuals like Reginald Reynolds and Ethel Mannin.
- Christian Høgsbjerg, "Mariner, renegade and castaway: Chris Braithwaite, seamen’s organiser and Pan-Africanist", Race & Class, Vol. 53, No. 2 (October–December 2011), pp. 36-57.
- Christian Høgsbjerg, "The inspiring fight of socialist seafarer Chris Braithwaite", Socialist Worker, 25 February 2014.
- Christian Høgsbjerg, "Chris Braithwaite", Encyclopedia of Afro-European Studies.
- "British Shipping (Assistance) Act (1935)". Making Britain. Open University. Retrieved 7 January 2018.
- George Padmore, "Chris Jones: Fighter for the Oppressed", New Leader, September 1944.
- Dorothy Rose du Boulay, Chris Braithwaite and the International African Service Bureau - talk by Chris Braithwaite's granddaughter at Rastafari in Motion, Black Cultural Archives, August 2016.
- Christian Høgsbjerg, Chris Braithwaite: Mariner, Renegade and Castaway (London: Socialist History Society / Redwords, 2014), ISBN 9781909026568
- Christian Høgsbjerg, Chris M Braithwaite Dictionary of Caribbean and Afro-Latin American Biography (Oxford: Oxford University Press, 2016).
- Black Salt: Britain's Black Sailors - Exhibition at Merseyside Maritime Museum in Liverpool which featured Chris Braithwaite in 2017-18.
- A Necessary Fiction - art exhibition by Basil Olton in Tower Hamlets, London in 2017-18 inspired by the life of Chris Braithwaite.