Castellammare di Stabia's 2026 population is now estimated at 61,867. In 1981, the population of Castellammare di Stabia was 70,685. Castellammare di Stabia experienced a decrease of -290 residents over the past year, marking an annual decline of -0.47%. These population values and projections come from Italy cities census series 1981 to 2021 via CityPopulation fallback access, Italy cities official estimate 2025 via CityPopulation fallback access and World Population Review Internal Projections .