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 Poland for 35 days between June and July 1992. Pawlak is also the only prime minister to occupy the position twice. The longest-serving prime minister was Donald Tusk, who held the premiership continuously from 16 November 2007 to 22 September 2014. To date, three women, Hanna Suchocka, Ewa Kopacz and Beata Szydło, have served and are serving as premier. Suchocka, along with Tadeusz Mazowiecki and Jerzy Buzek, are the only Polish premiers, as of yet, to be invited into the Club of Madrid. <br> Prime Minister of Poland The President of the Council of Ministers (Polish: "Prezes Rady Ministrów"), colloquially referred