The Sydney Harbour Federation Trust ("Harbour Trust") is an Australian Government agency established in 2001 to preserve and rehabilitate a number of defence and other Commonwealth lands in and around Sydney Harbour. These lands were off limits to the public, some for over 100 years. Over the last ten years, the Harbour Trust has remediated the lands and, with one exception, all are now publicly accessible.

The Harbour Trust has transformed the lands into urban parklands with walking tracks, lookouts and picnic areas. Precincts have been landscaped and services upgraded. Buildings and facilities have been renovated and leased to businesses as diverse as research institutes, restaurants and cafes, education providers, gymnasiums and office-based businesses. The Trust now offers short-term holiday accommodation at Headland Park in Mosman and Cockatoo Island which also boasts a camp ground with harbour and city views. An ecological sanctuary is being created at North Head Sanctuary at Manly.

Public programs run by the Harbour Trust include open days, guided and self guided tours, children’s activity trails, a popular audio tour of Cockatoo Island, children’s vacation activities and a wide range of publications, interpretive signage, documentaries and other explanatory material.

The Harbour Trust has implemented a comprehensive events program to promote and utilise its lands, particularly on Cockatoo Island, the largest island in the harbour. Events have included a three day music and cultural festival, contemporary art installations, a comedy festival, a component of the Sydney Festival and an international motocross competition. The island is a major venue for the Biennale of Sydney.

The lands managed by the Harbour Trust are:

• Cockatoo Island
  Cockatoo Island, New South Wales
  Cockatoo Island is the largest island in Sydney Harbour in Sydney, New South Wales, Australia. Located at the junction of the Parramatta and Lane Cove rivers, Cockatoo Island is a former imperial prison, industrial school, reformatory and gaol. It was also the site of one of Australia's biggest...
  
  
• Headland Park, Mosman (Middle Head, Georges Heights and Chowder Bay)
• North Head Sanctuary (Former School of Artillery, North Head, Manly)
• Woolwich Dock and Parklands
• Macquarie Lighthouse
  Macquarie Lighthouse
  The Macquarie Lighthouse, also known as South Head Upper Light, was the first, and is the longest serving, lighthouse site in Australia. It is located on Dunbar Head, Vaucluse near the entrance to Sydney Harbour. There has been a navigational aid in this vicinity since 1791 and a lighthouse near...
  
  
• Snapper Island
  Snapper Island, New South Wales
  Snapper Island is a 1.65 hectare island in Sydney Harbour, Australia. It lies in the main channel of the western section of the harbour, upstream of the Sydney Harbour Bridge, adjacent to the Sydney suburb of Drummoyne....
  
  
• Former Marine Biological Station, Watsons Bay
• HMAS Platypus Neutral Bay

A number of other bodies have responsibility for the management of lands around Sydney Harbour including the Sydney Harbour Foreshore Authority

Sydney Harbour Foreshore Authority

The Sydney Harbour Foreshore Authority is a statutory authority set up by the Government of New South Wales in order to maintain the Port Jackson foreshore area. It maintains 4 km² of waterfront real estate in the foreshore area including Darling Harbour and The Rocks...

 and the Sydney Harbour National Park

Sydney Harbour National Park

thumb|right|250px|[[Nielsen Park]]Sydney Harbour National Park is a national park comprising parts of Sydney Harbour, its foreshores and various islands. The park lies within the Sydney metropolitan area and was created in piecemeal fashion during the 20th century...

, both entities of the New South Wales State Government

Government of New South Wales

The form of the Government of New South Wales is prescribed in its Constitution, which dates from 1856, although it has been amended many times since then...

.