Admiralty House is the official residence of the governor-general of Australia in Sydney. It is located in the suburb of Kirribilli, on the northern foreshore of Sydney Harbour, and adjacent to Kirribilli House, which serves as the Sydney residence of the Australian Prime Minister. The large Victorian Regency and Italianate sandstone manor, completed in stages based on designs by James Barnet and Walter Liberty Vernon, occupies the tip of Kirribilli Point. Once known as "Wotonga", it has commanding views across Sydney Harbour to the Sydney Harbour Bridge and the Sydney Opera House. Admiralty House is regarded as the secondary residence of the governor-general, the main residence being Government House in Canberra, also known as Yarralumla.

Its current name originates in the fact that it served as the residence for the Commander-in-Chief of the Royal Navy's Australian Squadron from 1885 to 1913.

The original building on the site was completed, as a private dwelling, in mid-to-late 1843, by John George Nathaniel Gibbes, the then Collector of Customs for New South Wales and a member of the New South Wales Legislative Council. A portrait of Gibbes, painted in 1808, hangs in the house.

On 22 June 2004 Admiralty House was placed on the Commonwealth Heritage List.

Before the arrival of British settlers in Sydney Harbour, the Aboriginal Cammeraygal people lived along the Kirribilli and Milsons Point foreshores, and in the surrounding bushland. The area was a fertile fishing ground, and the name Kirribilli is derived from the Aboriginal word kiarabilli, which means "good fishing spot". The name Cammeraygal is displayed on the North Sydney Municipal Council emblem, and also gave name to the suburb of Cammeray.

Kirribilli was settled early in the history of the Colony. One of the first records of land being granted on the North Shore was 12 hectares (30 acres) on the North side of the Harbour of Port Jackson opposite Sydney Cove on 20 February 1794 to an expired convict, Samuel Lightfoot. Lightfoot was a former convict, born in about 1763 and transported to Australia for seven years for stealing clothing. He arrived with the First Fleet in 1788 on the Charlotte.

In 1794 Thomas Muir, a Scottish constitutional reformer, was sentenced to transportation for sedition. Thomas Muir purchased Lightfoot's farm. Muir also had a cottage on what is now Circular Quay. It is likely that the farm was located at the Jeffrey Street end of Kirribilli (not near Admiralty House) and was named "Huntershill" by Thomas Muir, after his father's home in Scotland. Thomas Muir escaped from the colony in 1796 aboard an American brig, the Otter.

Four years later the Colonial Secretary recorded that the land grant to Lightfoot was cancelled and given to Robert Ryan in 1800 with no mention of the intermediate (private) sale to Muir. Ryan had worked in Norfolk Island, both as a soldier and also a settler. The 12 hectares (30 acres) of Lightfoot's Grant was cancelled and included in a 49-hectare (120-acre) grant to Ryan for his service in the Royal Marines and the New South Wales Corps. The corresponding entry in the Register of Land Grants states Cancelled, and a New Grant given to Robert Ryan for 90 acres in addition to this Allotment, by Governor John Hunter. See the third Register, Folio 37. This grant to Ryan included almost all Kirribilli and later maps referred. By 1801, the property had passed into the hands of Robert Campbell, a wealthy Sydney merchant. Campbell built Australia's first shipbuilding yards in 1807, at the site that is now occupied by the Royal Sydney Yacht Squadron, Kirribilli. Part of the land in Kirribilli was also briefly used for quarantine purposes in 1814 for the convict ship Surry. Over 46 persons had died during the voyage of typhoid including 36 convicts.