Ardill was born in Belfast and educated at Coleraine Academical Institution. He later worked as the managing director of a feedstuffs company. He served in the Royal Irish Fusiliers from 1939 to 1946, winning the Military Cross for his bravery on the Greek island of Leros and retiring as a captain. He was a prisoner of war for 18 months before being freed by Allied troops after the D-Day landings. He also served as chairman of the Irish Temperance League.
After the war he became involved with the Ulster Unionist Party (UUP) and was elected as a member of Larne Rural District Council. In 1965 he was elected as a member of the Parliament of Northern Ireland, representing Carrick. He was opposed to the political reform programme of the Prime Minister Terence O'Neill and as a result lost the UUP nomination for Carrick in 1969 to Anne Dickson.
Subsequently, he became involved in the Ulster Vanguard movement, as one of its deputy leaders. The movement was launched on opposed to any further reforms which would threaten the status quo. When the movement broke away from the UUP to form a separate political party, Ardill chose to remain with the UUP.
In 1973, Ardill was elected to the Northern Ireland Assembly, representing South Antrim. Although he signed the pledge to support the former Prime Minister Brian Faulkner, he changed sides after the election to oppose the Sunningdale Agreement. Ardill was courted by the Democratic Unionist Party and considered switching to that party before ultimately deciding to remain an Ulster Unionist. He was re-elected for South Antrim in the Constitutional Convention election of 1975.
In the wake of the Anglo-Irish Agreement in 1985, he became involved in the Charter Group, a pressure group within the UUP which had the restoration of devolution as its main objective and accepted an Irish dimension in Northern Ireland politics. A close friend of Rev Martin Smyth, Ardill would briefly return to politics in the late 1990s when he joined Smyth in campaigning against the Belfast Agreement.
Betty Orr his daughter, was a schoolteacher who upon her retirement received praise for her work at the school where she taught and for building cross community links.
- Telegraph Obituaries, 13 October 2010
- "No. 37262". The London Gazette. 11 September 1945. p. 4560.
- "No. 38124". The London Gazette. 14 November 1947. p. 5420.
- Brief Biography Archived 25 July 2011 at the Wayback Machine
- Stormont election results
- Carrick election 1969
- Vanguard movement profile
- South Antrim results
- Steve Bruce, Paisley: Religion and Politics in Northern Ireland, Oxford University Press, 2007, p. 121
- 1979 UUP leadership election
- UUP Charter group profile
- "The children's champion... a class act" BBC News 26 March 2010 Retrieved 19 November 2012
- "Tributes paid to unionist stalwart" The Newsletter
|Parliament of Northern Ireland|
| Member of Parliament for Carrick
|Northern Ireland Assembly (1973)|
|New assembly|| Assembly Member for South Antrim
|Northern Ireland Constitutional Convention|
|New convention|| Member for South Antrim
|New political party|| Deputy Leader of Ulster Vanguard
With: Martin Smyth