Nikolayevsky District

Nikolayevsky District may refer to:
 * Nikolayevsky District, Russia, name of several districts in Russia
 * Mykolaiv Raion, Lviv Oblast, a former district of Lviv Oblast, Ukraine
 * Mykolaiv Raion, Mykolaiv Oblast, a district of Mykolaiv Oblast, Ukraine
 * Mykolaivka Raion, a district of Odesa Oblast, Ukraine