This is a list of Australian Leaders of the Opposition. The Leader of the Opposition in Australian Federal Politics is a Member of Parliament in the House of Representatives. The position is held by the leader of the party not in government that has the most seats in the House. When in parliament, the Leader of the Opposition sits on the left-hand side of the centre table, in front of the Opposition and opposite the Prime Minister. The Opposition Leader is elected by his or her party according to its rules. A new Opposition Leader may be elected when the incumbent dies, resigns, or is challenged for the leadership.
The Commonwealth of Australia is a constitutional monarchy with a parliamentary system and is based on the Westminster model. The term Opposition has a specific meaning in the parliamentary sense, with a formal title of Her Majesty's Loyal Opposition. It is an important component of the Westminster system, with the Opposition directing criticism at the Government and attempts to defeat and replace the Government. The Opposition is therefore known as the 'Government in waiting' and it is a formal part of the parliamentary system. It is in opposition to the Government, but not to the Crown; hence the term 'Loyal Opposition'.