Geoffrey O'Halloran Giles (27 June 1923 – 18 December 1990) was an Australian politician.He was born in Adelaide, South Australia, a son of Hew O'Halloran Giles, and Mrs. Giles (a daughter of Dr. W. A. Verco) of Thorngate, then "Willyama", Medindie and educated in Victoria at Geelong Grammar School before returning to South Australia to attend the University of Adelaide and Roseworthy College.