Udon Thani's 2026 population is now estimated at 611,342. In 1950, the population of Udon Thani was 16,129. Udon Thani has grown by 7,179 in the last year, which represents a 1.19% 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 Udon Thani, which typically includes Udon Thani's population in addition to adjacent suburban areas.
| City | 2026 Pop. ↓ | Growth |
|---|---|---|
| Bangkok | 11,543,900 | 1.34% |
| Chon Buri | 1,509,580 | 1.23% |
| Samut Prakan | 1,410,600 | 1.23% |
| Chiang Mai | 1,259,540 | 1.23% |
| Songkhla | 1,043,260 | 1.23% |
| Pathum Thani | 986,213 | 1.23% |
| Nakhon Ratchasima | 831,016 | 1.2% |
| Samut Sakhon | 624,139 | 1.23% |
| Chiang Rai | 593,585 | 1.23% |
| Rayong | 580,833 | 1.23% |
| Nakhon Pathom | 576,756 | 1.65% |
| Kalasin | 558,690 | 1.23% |
| Surat Thani | 535,306 | 1.23% |
| Lop Buri | 535,183 | 2.11% |
| Ubon Ratchathani | 534,017 | 1.23% |
| Buri Ram | 489,735 | 1.23% |
| Lampang | 485,131 | 1.23% |
| Phra Nakhon Si Ayutthaya | 476,244 | 1.23% |
| Roi Et | 475,554 | 1.23% |
| Phuket | 466,495 | 1.23% |
| Ratchaburi | 444,864 | 1.35% |
| Chanthaburi | 412,898 | 1.65% |
| Sakon Nakhon | 411,309 | 1.23% |
| Suphan Buri | 386,646 | 1.65% |
| Lamphun | 342,337 | 1.23% |
