Kostromskoy

Kostromskoy (masculine), Kostromskaya (feminine), or Kostromskoye (neuter) may refer to:
 * Kostromskoy District, a district of Kostroma Oblast
 * Kostromskoy (cheese), a type of Russian cheese
 * Kostroma Oblast (Kostromskaya oblast), a federal subject of Russia
 * Kostromskaya (rural locality), a rural locality (a stanitsa) in Krasnodar Krai, Russia
 * Kostromskoye, a rural locality (a selo) in Sakhalin Oblast, Russia