Every letter former governor-general Sir John Kerr wrote to Buckingham Palace will be released publicly.
The National Archives will publish the 212 letters plus attachments – more than 1000 pages – online next Tuesday.
The decision follows a four-year legal battle by historian Jenny Hocking to gain access to the documents.
The so-called ‘palace letters’ between Sir John and Buckingham Palace cover the time of Gough Whitlam’s dismissal.
The letters were due to become public in 2006 after falling within the ‘open access period’, but were deemed personal communications by the National Archives of Australia and the Federal Court.
Archives director-general David Fricker said the letters would be released in full, after staff examined them to check whether any information should be redacted.