Ust-Orda Buryat Okrug (; ), or Ust-Orda Buryatia, is an administrative division of Irkutsk Oblast, Russia. It was a federal subject of Russia (an autonomous okrug of Irkutsk Oblast) from 1993 to January 1, 2008, when it merged with Irkutsk Oblast. It also had autonomous okrug status from September 26, 1937 to 1993. Prior to the merger, it was called Ust-Orda Buryat Autonomous Okrug .