The General Post Office is a heritage-listed landmark building located in Martin Place, Sydney, New South Wales, Australia. The original building was constructed in two stages beginning in 1866 and was designed under the guidance of Colonial Architect James Barnet. Composed primarily of local Sydney sandstone, mined in Pyrmont, the primary load-bearing northern façade has been described as "the finest example of the Victorian Italian Renaissance Style in NSW" and stretches 114 metres (374 ft) along Martin Place, making it one of the largest sandstone buildings in Sydney.

Martin Place is a pedestrian mall in the Sydney central business district, New South Wales, Australia. Martin Place has been described as the "civic heart" of Sydney. As home to the Reserve Bank of Australia, the Commonwealth Bank, Macquarie Bank, Westpac and other corporations, it is also a centre of business and finance. The Sydney GPO is also located on Martin Place.