Archer was born to Richard Archer, from Barbados, and Mary Teresa Burns, from Ireland, in Liverpool. He travelled the world as a seaman, living in the USA and Canada, then settled in Battersea with his wife, Bertha, a black Canadian. He ran a small photographic studio at a time when photography was in its infancy.
Archer became involved in local politics and friendly with London radicals. In 1906 he was elected as a Liberal to Battersea Borough Council for Latchmere ward; at the same time, Williams won in Marylebone. He successfully campaigned for a minimum wage of 32 shillings a week for council workers and was re-elected in 1912. In 1913, he was nominated for the position of Mayor. There were negative, even racist, aspects to the campaign, with allegations that he did not have British nationality. He won by 40 votes to 39 and gave a notable victory speech:
Archer moved to the left during his years in Battersea and was re-elected to the Council as a Labour representative in 1919. He stood without success for parliament the same year. In 1918 he became President of the African Progress Union, working for black empowerment and equality. In 1919 he was a British delegate to the Pan-African Congress in Paris. Two years later he chaired the Pan-African Congress in London.
In 1922, Archer acted as Labour Party secretary election agent for Shapurji Saklatvala, a Communist activist standing for parliament in North Battersea. He convinced the Labour Party to endorse Saklatvala and he was duly elected one of the first black MPs in Britain. He and Saklatvala continued to work together, winning again in 1924 until the Communist and Labour parties split fully. In 1929, Archer was agent for the official Labour candidate who won in the general election, beating Saklatvala.
Archer served as a governor of Battersea Polytechnic, President of the Nine Elms Swimming Club, Chair of the Whitley Council Staff Committee and a member of the Wandsworth Board of Guardians. At the time of his death in 1932, he was deputy leader of Battersea council. He died on Thursday 14 July 1932, just a few weeks after his 69th birthday. His funeral was held at the Church of Our Lady of Carmel in Battersea Park Road on Tuesday 19 July, and was buried in the Council’s cemetery at Morden.
In 2004, John Archer was chosen for the 100 Great Black Britons list, coming 72nd in a public vote.