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
Office of the Prime Minister (Canada) Office of the Prime Minister (Canada) In Canada, the Office of the Prime Minister (more commonly referred to as the Prime Minister's Office and abbreviated as PMO), located in the Office of the Prime Minister and Privy Council building, facing Parliament Hill, in Ottawa, is one of the most powerful parts of the government. It is made up of the prime minister and his or her top political staff, who are charged with advising the prime minister on decisions, making the office a wholly partisan body. It should not be confused with the Privy Council Office (PCO), which is the