The Minister for Defence is a senior minister in the Government of Ireland and leads the Department of Defence. The current Minister for Defence is Micheál Martin, TD. He is also Minister for Foreign Affairs.

The Constitution of Ireland vests executive authority in the Government of Ireland, which is headed by the Taoiseach, the head of government. The government – also known as the cabinet – is composed of ministers, each of whom must be a member of the Oireachtas, which consists of Dáil Éireann and Seanad Éireann. Most ministers have a portfolio of specific responsibilities such as departments or policy areas, although ministers without portfolio can be appointed.