The Office of National Assessments (ONA) was an Australian statutory intelligence agency established by the Office of National Assessments Act 1977 as an independent statutory body directly accountable to the Prime Minister of Australia as a portfolio agency of the Department of the Prime Minister and Cabinet.

[2] ONA provided all-source assessments on international political, strategic and economic developments to the Prime Minister and the National Security Committee of Cabinet.

[3] The origins of ONA stem from recommendations of the Royal Commission on Intelligence and Security (also known as the First Hope Commission) which was established on 21 August 1974 by Australia's Prime Minister Gough Whitlam and led by Justice Robert Hope, for the formation of an independent agency to provide intelligence assessments on political, strategic and economic issues directly to the Prime Minister.

In 2003, in the lead-up to the 2003 invasion of Iraq, an ONA intelligence officer named Andrew Wilkie resigned from the agency, citing ethical concerns in relation to selective and exaggerated use of intelligence by the Australian Government on the matter of Iraq and weapons of mass destruction.

The ONA is divided into analytic branches covering geographic or thematic areas including: The Enterprise Management Group is led by a Deputy Director-General is responsible for interagency and intergovernmental intelligence coordination, integration and engagement functions and the governance and capability development of the Australian Intelligence Community.

EFIC also runs an active foreign relationship program and manages ONA's Cabinet liaison functions.

[13] EFIC supports the Department of the Prime Minister and Cabinet and the National Intelligence Coordination Committee.

The South Asia and Middle East Branch monitors and forecasts political, security, social, and economic developments, issues and trends in South Asia (including India, Pakistan, and Afghanistan) and the Middle East (including Iran, Iraq, Syria, Israel, and Saudi Arabia) and analyses and assesses all-source intelligence products on South Asia and Middle East from the Australian Intelligence Community.

[16] Maude took leave from ONA in 2017 to prepare the White Paper on Foreign Policy, with Bruce Miller acting in the role.

[18] Before its move, ONA had been a sub-tenant in the Central Office building of the Australian Security Intelligence Organisation (ASIO) in Russell, Canberra.