Killeen first held political office in 1985 when he was elected to
Clare County Council and served on that body until 1997. He was chairman of that local authority from 1989 to 1991. At the
1992 general election, he was elected to
Dáil Éireann as a Fianna Fáil TD for the
Clare constituency for the first time and retained his seat at each subsequent election until his retirement in 2011. Killeen has served on a number of committees, including the Joint Oireachtas Committee on Education and Science, the Committee on Procedure and Privileges and the Committee on Members' Interests in Dáil Éireann. In 2004, he was appointed as
Minister of State at the Department of Enterprise, Trade and Employment with special responsibility for Labour Affairs. In June 2007, he was appointed as
Minister of State at the Department of the Environment, Heritage and Local Government and
at the Department of Communications, Energy and Natural Resources with special responsibility for Environment and Energy. In May 2008, he was appointed as Minister of State at the
Department of Agriculture, Fisheries and Food with special responsibility for Fisheries and Forestry. In January 2007, it emerged that Killeen's office had sent letters to the
Minister for Justice, Equality and Law Reform advocating for the early release of a convicted child rapist. Killeen refused to resign as Minister of State. On 23 March 2010,
Taoiseach Brian Cowen appointed Killeen as
Minister of Defence replacing
Willie O'Dea who had resigned for
committing perjury in front of the High Court. On 6 January 2011, Killeen announced his decision not to contest the
2011 general election, citing medical advice, having been diagnosed with
bowel cancer in 2008. He resigned as Minister for Defence on 19 January 2011. ==References==