He was born in Wandsworth on 31 January 1903 and educated at St Catharine's College and Wesley House, Cambridge. In his student days he showed outstanding sporting prowess, gaining his colours in hockey, tennis, cricket, soccer and swimming. At Islington Central Hall he was a pioneer of cinema evangelism. He became Superintendent of the West London Mission in 1936, supervising its extensive social work for a total of 42 years and serving as chaplain at Holloway and Pentonville prisons. At Kingsway Hall he preached to large crowds. He became famous as an open-air orator on Tower Hill for a stint of over seventy years from 1927 on and also at Speakers' Corner in Hyde Park. His last appearance on Tower Hill was on December 2, 1998, less than a month before he died. He early established a reputation as a superb broadcaster. Despite an antipathy towards committee work and being ill at ease with the Methodist establishment, he was elected President of the 1953 Conference.
He played a leading part in the formation of the Order of Christian Witness in 1942. He was President of the Methodist Sacramental Fellowship, of the Methodist Peace Fellowship and of the Fellowship of Reconciliation. His pacifism and support of the Labour Party sprang directly from his understanding of the gospel. In 1965 he entered the House of Lords as the first Methodist minister to become a life peer. He was made an honorary fellow of St. Catharine's College, Cambridge in 1966 and awarded an honorary doctorate in 1988. In 1981 he received the annual World Methodist Peace Award and in 1988.was made a Freeman of the Haberdashers' Company and of the City of London. He was a gifted musician and for many years played the tin whistle at the annual Conference meeting of the National Children's Home.
He travelled throughout the world to preach and speak. In 1960 he gave the Lyman-Beecher Lectures on Preaching at Yale and in 1963, with Paul Tillich, the Earl Lectures at Berkeley, CA. In 1980 he gave the annual Tawney Lecture. For many years he wrote a monthly column in the Methodist Recorder under the title 'Personally Speaking'. In retirement he maintained a heavy programme of work, battling courageously into his nineties against loss of mobility through arthritis. He was the author of many books, especially on Christian apologetics and social concerns. His autobiography, Calling for Action was published in 1984. He died in London on 22 December 1998.
A bust by Ian Walters is on display in the vestibile at Wesley's Chapel.
'What G.K. Chesterton did for the Faith in print, and C.S. Lewis on the radio, Donald Soper achieved by soapbox oratory… Donald practised what he called the 'fellowship of controversy', delighting to argue the Christian case against all comers. His way with hecklers became the stuff of legend. He never stooped to score cheap points, but demolished their arguments with amiable wit, and often made them his friends. It was one of his sadnesses of his later years that the traditional Speaker's Corner hecklers had given place to humourless fundamentalists who hurled biblical texts like missiles at him, and hooligans trying to break up his meetings.'
Colin Morris, Snapshots (2007) p.30
'It still amazes me that this man could communicate so effectively with dockers on Tower Hill, tourists at Speakers' Corner, Lord Hailsham and Lord Denning on the Wogan Show and the likes of C.E.M. Joad, Malcolm Muggeridge and Bertrand Russell on the "Brains Trust". To straddle audiences as diverse as this in the open air, on television and on radio is surely an accomplishment of very rare merit.'
Leslie Griffiths in Methodist Recorder, 20 February 2015
'Whatever he turned his hand to, he did superbly well, whether delivering the Lyman Beecher Lectures on Preaching at Yale without a single note or playing the tin whistle at the annual Conference meeting of the National Children's Home.'
Colin Morris in Methodist Recorder 14 October 2016
Colin Morris in The Independent, 23 December 1998