GIO Building, Heritage office tower in Sydney central business district, Australia

GIO Building is a 10-story office tower located on Elizabeth Street in Sydney's business district. The facade displays geometric patterns and vertical lines inspired by American skyscrapers of the 1920s.

The site was part of a land grant made to Jacob Josephson on 5 April 1836; Josephson, a jeweller convicted of possessing forged bank notes, had reached Sydney in May 1818. By 1842 Wentworth Chambers stood on the land. Sun Newspapers Limited bought the property in 1927 and built the GIO Building in 1929 to house its offices and printing operations.

The building's name changed with its owner: opened for Sun Newspapers Limited, it passed on 15 June 1955 to the Government Insurance Office, which gave the tower the GIO name it still carries. The 1926 design competition was judged by Leslie Wilkinson and Kingsley Henderson, and Joseph Kethel's winning scheme was built with E. Leslie James as structural engineer.

Seven elevators connect the ten floors and provide easy access throughout the building. The property continues to serve as an active office complex in Sydney's central business district.

The structure was built using local materials including Benedict stone, Uralla granite, and Cudgegong marble, which showcase the craftsmanship of interwar architecture. This careful material selection highlights the building's connection to Australia's construction industry of that era.