Mitchell Peter Fifield (born 16 January 1967) is an Australian politician and diplomat who last served as the Permanent Representative of Australia to the United Nations.

[4] After the 2010 election, Fifield was appointed the Shadow Minister for Disabilities, Carers and the Voluntary Sector and Manager of Opposition Business in the Senate.

[5] Throughout his political career, Fifield has been an advocate of voluntary student unionism, as well as allowing women to serve on the front lines of the Australian Defence Force.

"[8] Following the 2013 federal election Fifield was appointed to the Abbott Ministry as the Assistant Minister for Social Services and the Manager of Government Business in the Senate.

In May 2019, following the Coalition's victory at the 2019 federal election, it was announced that Fifield would be appointed to succeed Gillian Bird as Permanent Representative of Australia to the United Nations.