The Administrative Appeals Tribunal (AAT) conducts independent merit reviews of administrative decisions made under Commonwealth laws.  AAT reviews decisions made by Australian Government ministers, departments and agencies and, in limited circumstances, decisions made by state government and non-government bodies. AAT also reviews decisions made under Norfolk Island laws.

The AAT was established by the Administrative Appeals Tribunal Act 1975 and commenced operations on 1 July 1976.

On 1 July 2015 the Migration Review Tribunal, Refugee Review Tribunal and Social Security Appeals Tribunal were merged with the AAT.

Merit review of an administrative decision involves considering afresh the facts, law and policy relating to that decision. The Tribunal considers the material before it and decides what is the correct – or, in a discretionary area, the preferable – decision. It will affirm, vary or set aside the decision under review.

The Tribunal is not always the first avenue of review of an administrative decision. In some cases, the Tribunal cannot review a decision until there has been an internal review of the primary decision. In other cases, review by the Tribunal is only available after intermediate review by a specialist tribunal – for example, an application for review of a family assistance or social security decision may be made only after review by the Social Security Appeals Tribunal.

Section 33 of the Administrative Appeals Tribunal Act requires that proceedings of the Tribunal be conducted with as little formality and technicality, and with as much expedition, as the requirements of the Act and a proper consideration of the matters before the Tribunal permit. The Tribunal is not bound by the rules of evidence and can inform itself in any manner it considers appropriate.