Chiayi County's 2026 population is now estimated at 469,324. In 2015, the population of Chiayi County was 519,839. Chiayi County experienced a decrease of -4,707 residents over the past year, marking an annual decline of -0.99%. These population values and projections come from Taiwan MOI household registration population by local administration (December snapshots) and World Population Review Internal Projections .
| City | 2026 Pop. ↓ | Growth |
|---|---|---|
| New Taipei | 4,056,148 | 0.11% |
| Taichung | 2,878,117 | 0.31% |
| Kaohsiung | 2,713,913 | -0.32% |
| Taipei | 2,431,249 | -1.2% |
| Taoyuan | 2,374,056 | 0.75% |
| Tainan | 1,849,281 | -0.25% |
| Changhua County | 1,207,402 | -0.75% |
| Pingtung County | 777,632 | -0.74% |
| Yunlin County | 648,791 | -0.73% |
| Hsinchu County | 607,326 | 1.06% |
| Miaoli County | 527,787 | -0.48% |
| Chiayi County | 469,324 | -0.99% |
| Nantou County | 463,691 | -0.92% |
| Hsinchu | 460,552 | 0.36% |
| Yilan County | 447,167 | -0.23% |
| Keelung | 358,304 | -0.43% |
| Hualien County | 311,051 | -0.69% |
| Chiayi | 260,113 | -0.39% |
| Taitung County | 207,713 | -0.6% |
| Kinmen County | 145,198 | 0.55% |
| Penghu County | 109,047 | 0.53% |
| Matsu (Lienchiang) County | 14,362 | 1.46% |
