Sir James Plimsoll, AC, CBE (25 April 1917 – 8 May 1987) was an Australian diplomat and public servant.

Plimsoll was appointed the Australian representative on the United Nations Commission for Unification and Rehabilitation of Korea (UNCURK) in 1950, during the Korean War.

In 1970, Plimsoll was appointed as Ambassador to the United States of America, a job normally reserved in Australia for senior ex-politicians.

In February 1980, Plimsoll was named High Commissioner to the United Kingdom, replacing political appointee Gordon Freeth.

[6] However, in November 1980 the government announced that his term would be cut short in order to appoint another political appointee, Vic Garland.

It was reported that the British foreign secretary Lord Carrington told a public function that Plimsoll had been "treated very shabbily", and that both Queen Elizabeth II and Prime Minister Margaret Thatcher had expressed their surprise at the shortness of his term.

[8][9] The Administrative and Clerical Officers Association, a leading public-sector union, described the appointment as "another example of the Fraser government's shoddy disregard for the career Public Service".

[15] He died on 8 May 1987 following another heart attack, hours after attending a ceremony marking the anniversary of the Battle of the Coral Sea.