Greenwich is located 7 kilometres (4 mi) north-west of the Sydney central business district, in the local government area of the Municipality of Lane Cove.

The suburb occupies a peninsula on the northern side of Sydney Harbour, at the opening of the Lane Cove River.

Parramatta River had been known as the 'Thames of the Antipodes' and other nearby suburbs were also named after Thames localities of Putney, Woolwich and Henley.

Early land grants were made to Samuel Lightfoot, a convict, in 1794, and William Gore, public servant, in 1813.

[4] In the 1830s George Green and his father Amaziah bought land in Greenwich, with access to the harbour, and along with others began a shipbuilding industry on the foreshore.

Mann was the first Chief Commissioner for Railways, the Superintendent of convicts at Cockatoo Island and the builder of Fitzroy Dock.

[4] Between the 1880s and the 1940s a number of successful dairies operated in Greenwich, run by the Anderson, Hogan, Mather and Clarke families.

Light industry was set up along the foreshores of Greenwich, including Shipbuilding, brickmaking, quarrying, and the Patent Asphaltum Company which refined bitumen and manufactured building materials.

[4] Today fuel products unloaded at Gore Bay are transferred by an underground pipe to the Clyde Refinery.

The tunnel was dug by the New South Wales Government Railways to Birchgrove to provide a reliable way to get electricity from the Pyrmont Power Station to the tram network on the north shore.

[7] The tunnel was excavated almost entirely from the Greenwich side, as the residents on Long Nose Point at Balmain (now Birchgrove) successfully objected to the noise of the compressor powering pneumatic drills.

Greenwich Sports Club, which was founded in 1936, organises football (soccer) for men, women and children and netball for girls.

[19] Greenwich falls within the Federal Parliament electoral division of North Sydney, currently represented by independent Kylea Tink, who defeated Trent Zimmerman, a member of the Liberal Party in 2022.