At the governmental level, United States–Australia relationships are formalized by the ANZUS treaty and Australia-United States Free Trade Agreement.

Ambassadors to Australia have traditionally been friends, political allies, or former business associates of the current President.

In 1942, President Franklin Delano Roosevelt's close associate and nominee to be U.S. Minister in Canberra, Edward J. Flynn, was forced to withdraw his nomination for the position following difficulties in the senate confirmation process.

[3] This arrangement has suited Australian governments, which welcome the ability of such Ambassadors to gain direct access to the President, bypassing the State Department.

However, this has often had the result of long periods without an appointed ambassador and additional delays in the Senate confirmation process, with the career diplomat deputy head of mission serving as Chargé d’Affaires ad interim, such as between February 2005 and August 2006, from September 2016 to February 2019, from January 2021 to July 2022 and since November 2024.