Ostrovnoy (; masculine), Ostrovnaya (; feminine), or Ostrovnoye (; neuter) is a toponym:
Urban localities Ostrovnoy, Murmansk Oblast, a closed town in Murmansk Oblast;
Rural localities Ostrovnoy, Primorsky Krai (or Ostrovnoye), a selo in Krasnoarmeysky District of Primorsky Krai Ostrovnoye, Altai Krai, a selo in Ostrovnovsky Selsoviet of Mamontovsky District in Altai Krai; Ostrovnoye, Chukotka Autonomous Okrug, a selo in Bilibinsky District of Chukotka Autonomous Okrug Ostrovnoye, Kaliningrad Oblast, a settlement in Timiryazevsky Rural Okrug of Slavsky District in Kaliningrad Oblast Ostrovnoye, Lebyazhyevsky District, Kurgan Oblast, a village in Lisyevsky Selsoviet of Lebyazhyevsky District in Kurgan Oblast; Ostrovnoye, Mishkinsky District, Kurgan Oblast (or Ostrovnaya), a selo in Ostrovninsky Selsoviet of Mishkinsky District in Kurgan Oblast; Ostrovnoye, Orenburg Oblast, a selo in Novocherkassky Selsoviet of Saraktashsky District in Orenburg Oblast Ostrovnoye, Sverdlovsk Oblast, a settlement under the administrative jurisdiction of the City of Beryozovsky in Sverdlovsk Oblast Ostrovnaya, Omsk Oblast, a village in Khutorsky Rural Okrug of Tyukalinsky District in Omsk Oblast;
Other Bolshoye Ostrovnoye, a lake in Altai Krai Mayak-Ostrovnoy (sometimes referred to as Ostrovnoy), a lighthouse classified as an inhabited locality in Lazovsky District of Primorsky Krai