Siheung's 2026 population is now estimated at 452,423. In 1950, the population of Siheung was 1,571. Siheung has grown by 1,665 in the last year, which represents a 0.37% annual change. These population estimates and projections come from the latest revision of the UN World Urbanization Prospects . These estimates represent the Urban agglomeration of Siheung, which typically includes Siheung's population in addition to adjacent suburban areas.
| City | 2026 Pop. ↓ | Growth |
|---|---|---|
| Seoul | 10,050,200 | 0.24% |
| Busan | 3,492,730 | 0.24% |
| Incheon | 2,884,820 | 0.39% |
| Daegu | 2,184,070 | 0.14% |
| Gwangju | 1,540,890 | 0.27% |
| Gwangju | 1,540,890 | 0.27% |
| Daejeon | 1,538,394 | 1.01% |
| Suwon | 1,194,313 | 1.03% |
| Changwon | 1,059,130 | 0.2% |
| Ulsan | 918,482 | 0.24% |
| Cheonan | 717,256 | 0.55% |
| Jeonju | 669,579 | 0.25% |
| Namyangju | 629,061 | 1.04% |
| Gumi | 402,995 | 0.47% |
| Pohang | 368,816 | 0.36% |
| Wonju | 330,854 | 1.01% |
| Asan | 319,929 | 1.03% |
| Iksan | 301,723 | 1% |
| Yangsan | 297,532 | 1.04% |
| Chuncheon | 281,596 | 1.01% |
| Gunsan | 275,155 | 1.01% |
| Yeosu | 273,761 | 1% |
| Suncheon | 265,390 | 1.01% |
| Gyeongju | 262,310 | 1.01% |
| Mokpo | 239,524 | 0.99% |
| Gangneung | 215,677 | 1% |
| Osan | 213,840 | 1.03% |
| Yangju | 205,988 | 1.02% |
| Sejong | 204,088 | 1.2% |
| Anseong | 194,765 | 1.02% |
| Seosan | 169,221 | 1.02% |
| Andong | 168,581 | 1% |
| Hanam | 154,838 | 1.02% |
| Seogwipo | 153,861 | 1.03% |
| Gimcheon | 137,540 | 1.02% |
| Nonsan | 124,246 | 1.01% |
| Gongju | 113,542 | 0.99% |
| Jeongeup | 110,627 | 1% |
| Yeoju | 109,937 | 1.02% |
| Miryang | 103,069 | 1.01% |
| Sangju | 98,760 | 1% |
| Naju | 92,582 | 1.04% |
| Sokcho | 79,846 | 1% |
| Mungyeong | 71,863 | 1.01% |