Early life and career
Born in Belfast and educated locally, Cardwell worked as the manager of a coal importing firm. In 1952 he was elected to Belfast Corporation for Victoria Ward and later became an Alderman. During the 1960s Cardwell chaired the committee which was responsible for children's homes in the city. In 1969 he was elected to the Parliament of Northern Ireland for Belfast Pottinger  as an 'O'Neill Unionist' supporting the reform proposals of the then Prime Minister. He remained a member until the Parliament was prorogued in 1972. In 1973 he was elected to the Northern Ireland Assembly for Belfast East, as a Unionist pledged to support the former Prime Minister Brian Faulkner. When the Ulster Unionist Party split in 1974, Cardwell became a founder member of the Unionist Party of Northern Ireland and was returned for Belfast East in the 1975 Constitutional Convention election.
He remained a member of Belfast City Council until his death, representing 'Area B' equivalent to the current Victoria area.
Kincora Boys' Home abuse scandal
In March 1982, Cardwell was questioned by police in relation to his visits to Kincora Boys' Home, which had seen a child sex abuse scandal. The Hughes report into the scandal noted that Cardwell told the police of one conversation with the Belfast Town Clerk, who had mentioned an imprecise allegation of homosexual conduct (which at that time would have been illegal in Northern Ireland), but he said that no formal complaint had ever come his way. Shortly after the police interview Cardwell's body was found in a car in the garage of his home in Belfast, and he was found to have died of carbon monoxide poisoning; the coroner stated that the death was "inexplicable". Others regarded it as suicide.
The Hughes report concluded "There is no evidence that Councillor Cardwell took steps to prevent an investigation or suppress the matter." It mentioned that, as a member (and chairman) of the Welfare Committee, Cardwell had statutory visiting responsibilities in relation to homes.
The Josh Cardwell Centre, providing rehabilitation services in East Belfast, was named in his honour, but this closed in 2007.
On the 9th May 2017, the Josh Cardwell Centre burned down in a fire 
- Biographies of Members of the Northern Ireland House of Commons
- "Kincora file conspicuously absent from government records", Sam McBride, News Letter 3 January 2013
- Northern Ireland Parliamentary Election Results: Belfast
- The Local Government Elections 1973–1981: Belfast, Northern Ireland Elections
- Hughes, W.H. (1986) Report of the Inquiry into Children's Homes and Hostels, Belfast: HMSO, p70
- Lobster magazine, September 1983
- Margaret Scanlan, Plotting Terror: Novelists and Terrorists in Contemporary Fiction
- Hughes, W.H. (1986) Report of the Inquiry into Children's Homes and Hostels, Belfast: HMSO, p93
- Annual Report, Green Park Healthcare Trust
- , BBC Northern Ireland
|Parliament of Northern Ireland|
|Member of Parliament for Belfast Pottinger
|Northern Ireland Assembly (1973)|
|New assembly||Assembly Member for East Belfast
|Northern Ireland Constitutional Convention|
|New convention||Member for East Belfast