Ostjor (disambiguation)
Ostjor is
- the name of a river in Russia and Belarus, see Ostjor
- the Russian name of the Ukrainian river Oster, see Oster (Desna)
- the name of an urban-type settlement in the Russian Oblast of Smolensk, see Ostjor (Smolensk)
- the Russian name of the Ukrainian place Oster, see Oster (city)