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.