The National Tribunal was a series of military tribunals, held by the judiciary of the Cygnian Provisional Government under the same name following the conclusion of the Great Australian War. It was most notable for the prosecution of prominent members of the political, military, judiciary and economic leadership of the Democratic Republic of Cygnia. The Tribunal was presided by Arthur G. Cheswick.
The trials included, among others, former Chancellor and NCSP General Secretary Franklin J. Heller, the two surviving Chief Ministers (Frederick Poole and Max Nielsen), Central Commissar for War Montgomery Garrick, Central Commissar for National Security and Director of the Department for Military Intelligence Nathan S. Greene, Central Commissar for Finance Felix Warwick, Fleet Admiral Joseph Fairfield and Central Commissar for Justice Carl Altenberg. Of the forty tried, twenty-nine were found guilty of conspiring to accomplish a crime against peace, thirteen of war crimes, four of crimes against humanity, and eight of high treason against the former Empire of Cygnia government. Of those tried, ten were sentenced to death, including Heller. All ten were executed on 7 April 1947.