Sir John Greig Latham GCMG QC (26 August 1877 – 25 July 1964) was an Australian lawyer, politician, and judge who served as the fifth Chief Justice of Australia, in office from 1935 to 1952.
He had earlier served as Attorney-General of Australia under Stanley Bruce and Joseph Lyons, and was Leader of the Opposition from 1929 to 1931 as the final leader of the Nationalist Party.
Latham was born in Melbourne.
He studied arts and law at the University of Melbourne, and was called to the bar in 1904.
He soon became one of Victoria's best known barristers.
In 1917, Latham joined the Royal Australian Navy as the head of its intelligence division.
He served on the Australian delegation to the 1919 Paris Peace Conference, where he came into conflict with Prime Minister Billy Hughes.
At the 1922 federal election, Latham was elected to parliament as an independent on an anti-Hughes platform.
He got on better with Hughes' successor Stanley Bruce, and formally joined the Nationalist Party in 1925, subsequently winning promotion to cabinet as Attorney-General.
He was also Minister for Industry from 1928, and was one of the architects of the unpopular industrial relations policy that contributed to the government's defeat at the 1929 election.
Bruce lost his seat, and Latham was reluctantly persuaded to become Leader of the Opposition.
In 1931, Latham led the Nationalists into the new United Australia Party, joining with Joseph Lyons and other disaffected Labor MPs.
Despite the Nationalists forming a larger proportion of the new party, he relinquished the leadership to Lyons, a better campaigner, thus becoming the first opposition leader to fail to contest a general election.
In the Lyons Government, Latham was the de facto deputy prime minister, serving both as Attorney-General and Minister for External Affairs.
He retired from politics in 1934, and the following year was appointed to the High Court as Chief Justice.
From 1940 to 1941, Latham took a leave of absence from the court to become the inaugural Australian Ambassador to Japan.
He left office in 1952 after almost 17 years as Chief Justice; only Garfield Barwick has served for longer.