Nizhneudinsky (masculine), Nizhneudinskaya (feminine), or Nizhneudinskoye (neuter) may refer to: Nizhneudinsky District, a district of Irkutsk Oblast, Russia Nizhneudinskoye Urban Settlement, a municipal formation which the town of Nizhneudinsk in Nizhneudinsky District of Irkutsk Oblast, Russia is incorporated as