Udon Thani's 2026 population is now estimated at 1,524,495. In 2005, the population of Udon Thani was 1,506,165. Udon Thani experienced a decrease of -7,684 residents over the past year, marking an annual decline of -0.5%. 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% |
| Nakhon Sawan | 986,863 | -0.99% |
| Kalasin | 956,122 | -0.39% |
| Phetchabun | 946,454 | -0.65% |
| Maha Sarakham | 920,112 | -0.63% |
| Nakhon Pathom | 910,903 | 0.02% |
| Ratchaburi | 828,345 | -0.32% |
| Narathiwat | 821,277 | 0.26% |
| Phra Nakhon Si Ayutthaya | 818,496 | 0.01% |
| Phitsanulok | 815,655 | -0.81% |
| Kanchanaburi | 811,072 | -0.18% |
| Suphan Buri | 807,675 | -0.62% |
| Rayong | 785,287 | 1.1% |
| Pattani | 742,156 | 0.37% |
| Chachoengsao | 731,207 | 0.3% |
| Nakhon Phanom | 711,558 | -0.12% |
| Lopburi | 707,632 | -0.91% |
| Lampang | 690,572 | -0.9% |
| Kamphaeng Phet | 685,007 | -0.79% |
| Saraburi | 632,430 | -0.16% |
| Trang | 630,314 | -0.26% |
| Loei | 625,814 | -0.3% |
| Samut Sakhon | 566,307 | 0.42% |
| Sukhothai | 563,414 | -0.76% |
| Yala | 557,408 | 0.59% |
| Sa Kaeo | 552,488 | -0.26% |
| Tak | 550,686 | 0.18% |
| Prachuap Khiri Khan | 538,632 | -0.09% |
| Chanthaburi | 529,080 | -0.14% |
| Yasothon | 523,697 | -0.36% |
| Phatthalung | 516,981 | -0.21% |
| Phichit | 511,825 | -0.65% |
| Chumphon | 503,093 | -0.11% |
| Nong Khai | 502,340 | -0.42% |
| Nong Bua Lamphu | 501,575 | -0.3% |
| Prachin Buri | 500,511 | 0.19% |
| Krabi | 481,986 | 0.22% |
| Phetchaburi | 475,476 | -0.17% |
| Nan | 467,865 | -0.26% |
| Phayao | 444,766 | -0.78% |
| Uttaradit | 428,574 | -0.76% |
| Bueng Kan | 417,569 | -0.2% |
| Phrae | 415,637 | -0.85% |
| Phuket | 409,506 | 0.15% |
| Lamphun | 388,822 | -0.49% |
| Amnat Charoen | 370,623 | -0.27% |
| Mukdahan | 346,134 | -0.17% |
| Satun | 327,030 | 0.17% |
| Uthai Thani | 317,170 | -0.48% |
| Chai Nat | 307,199 | -0.86% |
| Ang Thong | 263,012 | -0.85% |
| Phang Nga | 261,659 | -0.16% |
| Nakhon Nayok | 258,460 | -0.05% |
| Mae Hong Son | 243,648 | 0.16% |
| Trat | 214,702 | -0.39% |
| Sing Buri | 195,207 | -0.91% |
| Samut Songkhram | 182,770 | -0.66% |
| Ranong | 181,385 | 0.25% |
