Pervomaisky district is located in the northern part of the Mykolaiv region, at the intersection of historical and ethnographic territories of the Black Sea coast, the Middle Dnieper and Podillya. The Southern Bug River flows within the district. The Migi rapids on the Southern Buz are part of the Bug Guard National Nature Park, whose administration is located in Migi. It is the largest rafting center in Ukraine.
The administrative center of Pervomaisky district is the city of Pervomaisk. The area of the district is 3797 square kilometers. The population of the district reaches 152 thousand people.
The Pervomaisky district includes 140 settlements, which are united into 8 territorial hromadas: Pervomaisk city, Arbuzynska, Vradiyivska, Kryvoozerska settlements, Blagodatnenska ...