Mykolaiv's 2025 population is now estimated at 476,414. In 1950, the population of Mykolaiv was 168,314. Mykolaiv experienced a decrease of -1,816 residents over the past year, marking an annual decline of -0.38%.These population estimates and projections come from the latest revision of the UN World Urbanization Prospects. These estimates represent the Urban agglomeration of Mykolaiv, which typically includes Mykolaiv's population in addition to adjacent suburban areas.