Sisak's 2026 population is now estimated at 36,770. In 2011, the population of Sisak was 47,768. Sisak experienced a decrease of -647 residents over the past year, marking an annual decline of -1.73%. These population values and projections come from Croatian Bureau of Statistics city census populations (2011 and 2021) and World Population Review Internal Projections .
| City | 2026 Pop. ↓ | Growth |
|---|---|---|
| Zagreb | 755,938 | -0.29% |
| Split | 152,472 | -1.03% |
| Rijeka | 98,914 | -1.74% |
| Osijek | 90,933 | -1.14% |
| Zadar | 68,730 | -0.59% |
| Velika Gorica | 59,889 | -0.39% |
| Pula - Pola | 49,782 | -0.95% |
| Karlovac | 46,488 | -1.2% |
| Slavonski Brod | 45,824 | -1.69% |
| Varazdin | 42,281 | -0.7% |
| Dubrovnik | 41,045 | -0.25% |
| Sibenik | 40,847 | -0.84% |
| Kastela | 37,365 | -0.23% |
| Samobor | 37,336 | -0.05% |
| Sisak | 36,770 | -1.73% |
| Bjelovar | 34,485 | -1.03% |
| Vinkovci | 28,824 | -1.35% |
| Koprivnica | 27,507 | -0.76% |
| Cakovec | 27,131 | 0.01% |
| Solin | 25,344 | 0.38% |
