Izhevsk Wikipedia. Izhevsk (Russian: Иже́вск, IPA: [ɪˈʐɛfsk]; Udmurt: Иж, Iž, or Ижкар, Ižkar) is the capital city of Udmurtia, Russia, located along the Izh River in the Western Ural Mountains.Its population is 629,455 (2012 est.), up from 627,734 recorded in the 2010 Census, making it the nineteenth-largest city in Russia and the largest in the republic.