Prime Minister of Australia prime minister, otherwise William McMahon63. Robert Menzies was the oldest person to ever be prime minister, leaving office at 71 years old. The longest-serving Prime Minister was Sir Robert Menzies, who served in office twice: from 26 April 1939 to 28 August 1941, and again from 19 December 1949 to 26 January 1966. In total Robert Menzies spent 18 years, 5 months and 12 days in office. He served under the United Australia Party and the Liberal Party respectively. The shortest-serving Prime Minister was Frank Forde, who was appointed to the position on 6 July 1945 after the death of
Prime Minister of Malaysia in a caretaker capacity. From time to time prime ministers are required to leave the country on business and a deputy is appointed to take their place during that time. In the days before jet aeroplanes, such absences could be for extended periods. Colour key (for political coalitions): Prime ministers are usually granted certain privileges after leaving office at government expense. Former prime ministers continue to be important national figures. The most recently deceased prime minister was Tunku Abdul Rahman (1903–1990), who died on 6 December 1990. Currently the oldest living former prime minister is Abdullah Ahmad Badawi at the