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 (Thailand) in the execution of their duties and helps them manage and formulate policies. It also acts as the cabinet office, recording and assisting the cabinet as a central functioning organ of the government. The prime minister must appoint a minister in charge, who is also a member of the cabinet, to oversee its operations. It also houses the offices of the various deputy prime ministers of Thailand. The office is in the Government House Complex, in Dusit, Bangkok. In late-2016, the OPM acquired an additional function: as a "holding pen" for government officials accused of corruption. Prime Minister Prayut Chan-o-cha