List of prime ministers of Australia by age  This is a list of Prime Ministers of Australia by age, including when they were born, what age they were when they were appointed prime minister, what age were they when they left the office and the age at which they died, or their current age as of if they are still alive. The table can be sorted by each different category. The date of appointment as prime minister is the date on which they were sworn in by the Governor-General for their first term. The day on which they departed office is the final day of their final term. This is either the day a new prime minister was appointed or their date of death if they died whilst in office. The median age of a Prime Minister on the first day of their first term is 52 years, and 353 days which falls between Joseph Cook and Billy Hughes. The youngest person to assume the office was Chris Watson (age 37 years, 18 days). The oldest person to assume office was John McEwen (age 67 years, 265 days). The oldest living former Prime Minister is John Howard, born 26 July 1939 (age ). The youngest living former Prime Minister is Julia Gillard, born 29 September 1961, (age ). The youngest living Prime Minister is the incumbent Scott Morrison, born 13 May 1968, (age ). The longest-lived Prime Minister was Gough Whitlam who died on 21 October 2014 at the age of 98 years, 102 days. Frank Forde was the second longest-lived Prime Minister, at the age of 92 years, 194 days. Whitlam surpassed Forde's lifespan on 21 January 2009. The oldest living Prime Minister, John Howard, will tie Whitlam if he lives to 5 November 2037. The shortest-lived Prime Minister was Harold Holt, at the age of 59 years, 134 days (See footnote below explaining his disappearance). The Prime Minister with the longest retirement is Gough Whitlam. He left office on 11 November 1975, and died 38 years, and 344 days later on 21 October 2014. The prime minister with the shortest retirement is Ben Chifley, who died on 13 June 1951, 1 year and 176 days after leaving office on 19 December 1949. This is a chronological list of all who served as the Prime Minister of Australia and were still living, at different periods in history. There has been one time period each when there was either one, two, or three living prime ministers, beginning with the appointment of Edmund Barton in 1901 and ending with the appointment of George Reid in 1904. There have been two time periods when 9 living current or former prime ministers co-existed.