Phra Nakhon Si Ayutthaya's 2026 population is now estimated at 818,496. In 2005, the population of Phra Nakhon Si Ayutthaya was 736,868. Phra Nakhon Si Ayutthaya has grown by 60 in the last year, which represents a 0.01% annual change. These population values and projections come from Thailand DOPA registered population by province (December snapshots) and World Population Review Internal Projections .
| City | 2026 Pop. ↓ | Growth |
|---|---|---|
| Bangkok | 5,186,582 | -0.98% |
| Nakhon Ratchasima | 2,599,753 | -0.24% |
| Ubon Ratchathani | 1,847,979 | -0.17% |
| Khon Kaen | 1,756,308 | -0.35% |
| Chiang Mai | 1,630,451 | -0.01% |
| Chon Buri | 1,619,225 | 0.74% |
| Buri Ram | 1,549,564 | -0.4% |
| Udon Thani | 1,524,495 | -0.5% |
| Nakhon Si Thammarat | 1,520,118 | -0.36% |
| Si Sa Ket | 1,429,315 | -0.42% |
| Songkhla | 1,415,421 | -0.1% |
| Samut Prakan | 1,363,410 | 0.4% |
| Surin | 1,339,850 | -0.58% |
| Nonthaburi | 1,326,991 | 0.79% |
| Roi Et | 1,271,250 | -0.36% |
| Pathum Thani | 1,242,738 | 1.06% |
| Chiang Rai | 1,156,893 | -0.22% |
| Sakon Nakhon | 1,133,052 | -0.24% |
| Chaiyaphum | 1,091,126 | -0.58% |
| Surat Thani | 1,070,934 | 0.14% |
