The building was completed in 1994, and officially opened by the Governor-General of Australia, Bill Hayden on 18 August 1994.

[1] The former Northern Territory Legislative Council established in 1948 was housed in various temporary buildings around Darwin until 1955, when the former site of the Palmerston Post Office, destroyed in the Bombing of Darwin in World War II, was redeveloped to house the Council.

After 1974, the Northern Territory Legislative Assembly continued to operate from the site and adjacent government buildings.

[1][2] The current building was constructed between 1990 and 1994 as a part of State Square, which also includes the Supreme Court, car parks and landscaping at a total cost at the time of around $170 million.

[2] The colour scheme of the Legislative Assembly Chamber is green with eucalyptus motifs on the walls, commemorating the similar shading of the Australian House of Representatives, itself commemorating the brighter green of the House of Commons of the United Kingdom.