Wilton's father was James McElmunn Wilton, an Ulster Unionist Party politician and Mayor of Londonderry. Claude Wilton was born in Eden Terrace, Derry. He was educated at Foyle College and Trinity College, Dublin where he studied law for three years. After qualifying as a solicitor, he operated his own practice at Waterloo Place and, later, in Great James' Street in Derry. Wilton retained his Protestant faith, but channelled his activities into the Civil Rights Movement. He was elected as an officer of the Derry Citizen's Action Committee (DCAC) in late 1968 and called for Protestants in Derry to "stand up and be counted" in regard to the early campaign for civil rights in Northern Ireland. He worked as one of Derry's best-known solicitors and often represented the poor and underprivileged.
Wilton was disappointed at the decision of the Unionist Stormont government not to locate the province's second university in Derry. He regarded it as another example of government's neglect of a predominantly Republican and Catholic city. He decided to stand for election at the Northern Ireland general election, 1965 in the City of Londonderry seat for the Ulster Liberal Party. The seat was held by a Unionist, who had been unopposed in recent elections. Wilton polled 47% of the vote.
At the Northern Ireland general election, 1969, Wilton stood again in the City of Londonderry. According to Ivan Cooper, he used the slogan "Vote for Claude the Catholic prod". He was reduced to 35.1% of the votes cast, but reduced the Unionist majority to 710 votes and narrowly missed being elected. Immediately after the election, he was elected to the Senate of Northern Ireland, remaining a member until the body was prorogued in 1972. While serving as a Senator, he joined the Social Democratic and Labour Party.
- Erin Hutcheon, Death of a Derry legend, Claude Wilton", Derry Journal, 26 September 2008
- "Chapter from 'Ulster's White Negroes' by Fionnbarra Ó Dochartaigh". CAIN web service. United Kingdom. Retrieved 25 September 2008.
- "Calendar of Newspaper Articles dealing with Civil Rights issues, 1 Jun 1968 - 9 Dec 1968 by Alan Scott". CAIN web service. United Kingdom. Retrieved 25 September 2008.
- "Derry lawyer and campaigner dies". BBC News. United Kingdom: BBC. 2008-09-25. Retrieved 25 September 2008.
- Berkley Farr, Obituary of Claude Wilton, Liberal Democrat News, 3 October 2008
- Northern Ireland Parliamentary Elections Results: Boroughs: Londonderry
- The Northern Ireland Senate, 1921-72, Northern Ireland Elections
- Richard Deutsch, Northern Ireland 1969-73 a chronology of events