GDP per Capita and Population Data for the Provinces of Thailand
Here are the GDP figures for 2018 in all the provinces of Thailand by region (latest data available at NESDB, year 2020). Numbers are Thai baht (real) in 2018.
There may be minor changes in these numbers in the following years. In a sense, recent published data always remain preliminary.
Source : Gross Regional and Provincial Product Chain Volume Measure 2018 Edition, NESDB
In the Executive Summary of this publication, we found the following statement for the year 2018 (latest year data are available for) :
Increased growth in almost all regions. Bangkok and its vicinities showed the highest growth rate at 5.0 %, followed by the North (4.8 %), the West (4.5 %), the South 4.4 %, and the Northeast (3.4 %). The East and the Central Region increased at lower rates of 2.8 % and 1.1 % respectively.
Some observations : Of the 10 provinces with the lowest per capita income, 8 are located in the North Eastern Region. But the poorest province is Mae Hong Son in the North.
The difference in between the regions, and in between the provinces in certain regions, are simply astounding.
The average GDP for the whole Kingdom of Thailand in 2018 was 236,815 Thai Baht.
Population figures below are the ones estimated by NESDB for 2018.
For the whole Kingdom, the population in 2018 is estimated at 69.107 million. You may find other numbers at other sources, but we understand there has not been a census for a while.

GDP per capita in 2018 for Northeastern Region.
North Eastern Region | 83,856 | 18,595 |
Province : |
GDP per capita : | Population: (thousands) |
1. Loei | 100,796 | 543 |
2. Nong Bua Lamphu | 60,776 | 478 |
3. Udon Thani | 88,194 | 1,266 |
4. Nongkhai | 92,825 | 456 |
5. Sakon Nakhon | 64,084 | 925 |
6. Nakhon Phanom | 78,802 | 561 |
7. Chaiyaphum | 69,730 | 942 |
8. Khon Kaen | 122,950 | 1,718 |
9. Kalasin | 73,998 | 801 |
10. Mukdahan | 62,766 | 404 |
11. Maha Sarakham | 75,418 | 792 |
12. Roiet | 70,803 | 1,068 |
13. Yasothon | 60,055 | 463 |
14. Amnat Charoen | 68,742 | 282 |
15. Nakhon Ratchasima | 117,517 | 2,515 |
16. Buriram | 67,142 | 1,228 |
17. Surin | 70,556 | 1,076 |
18. Sisaket | 73,958 | 980 |
19. Ubon Ratchathani | 71,469 | 1,738 |
20. Bueng Kan* | 67,476* | 360* |
* The province of Bueng Kan was created in 2011. I lies adjacent to Nongkhai province and was previously part of that province. |

GDP per capita in 2018 for Central Region
GDP per capita in 2018 for Bangkok and Vicinity
Central Region | 271,759 | 3,177 |
Province : |
GDP per capita : | Population: (thousands) |
1. Chainat | 119,850 | 294 |
2. Singburi | 145,899 | 190 |
3. Lopburi | 142,741 | 777 |
4. Ang Thong | 122,159 | 250 |
5. Ayutthaya | 454,953 | 907 |
6. Saraburi | 324,820 | 758 |
Bangkok and Vicinity | 457,399 | 16,763 |
Province : |
GDP per capita : | Population: (thousands) |
7. Nakhon Pathom | 294,361 | 1,186 |
8. Nonthaburi | 188,822 | 1,722 |
9. Pathum Thani | 233,593 | 1,729 |
10. Samut Sakhon | 389,818 | 1,042 |
11. Bangkok Metropolis | 604,421 | 8,912 |
12. Samut Prakarn | 366,642 | 2,171 |

GDP per capita in 2018
for Eastern Region
Eastern Region | 508,568 | 5,951 |
Province : |
GDP per capita : | Population: (thousands) |
1. Nakhon Nayok | 116,717 | 259 |
2. Prachinburi | 513,789 | 621 |
3. Sa Kaew | 80,716 | 630 |
4. Chachoengsao | 469,539 | 823 |
5. Chonburi | 566,801 | 1,819 |
6. Rayong | 1,067,449 | 980 |
7. Chanthaburi | 217,393 | 553 |
8. Trat | 161,322 | 267 |

GDP per capita in 2018 for Northern Region.
Northern Region | 110,897 | 11,422 |
Province : |
GDP per capita : | Population: (thousands) |
1. Mae Hong Son | 58,370 | 235 |
2. Chiang Mai | 137,316 | 1,805 |
3. Chiang Rai | 95,895 | 1,156 |
4. Phayao | 97,306 | 383 |
5. Nan | 75,676 | 445 |
6. Lamphun | 211,489 | 399 |
7. Lampang | 100,709 | 714 |
8. Phrae | 78,276 | 388 |
9. Tak | 99,026 | 532 |
10. Sukhothai | 82,147 | 613 |
11. Uttaradit | 94,260 | 416 |
12 Kamphaengphet | 150,783 | 781 |
13. Phitsanulok | 111,872 | 896 |
14. Uthai Thani | 106,369 | 281 |
15. Nakhon Sawan | 123,865 | 938 |
16. Phichit | 93,265 | 518 |
17. Phetchabun | 88,971 | 921 |

GDP per capita in 2018 for Southern Region
Southern Region | 147,115 | 9,535 |
Province : |
GDP per capita : | Population: (thousands) |
1. Chumphon | 176,200 | 498 |
2. Ranong | 103,966 | 269 |
3. Surat Thani | 182,371 | 1,134 |
4. Phang Nga | 313,919 | 250 |
5. Krabi | 207,415 | 418 |
6. Nakhon Si Thammarat | 109,050 | 1,507 |
7. Trang | 102,589 | 630 |
8. Phuket | 403,534 | 580 |
9. Phatthalung | 73,213 | 492 |
10. Satun | 107,505 | 290 |
11. Songkhla | 151,918 | 1,635 |
12. Pattani | 75,697 | 641 |
13. Yala | 91,815 | 468 |
14. Narathiwat | 62,066 | 721 |

GDP per capita in 2018 for Western Region
Western Region | 158,206 | 3,665 |
Province : |
GDP per capita : | Population: (thousands) |
1. Kanchanaburi | 129,304 | 829 |
2. Suphanburi | 107,228 | 854 |
3. Ratchaburi | 233,258 | 813 |
4. Samut Songkhram | 142,808 | 182 |
5. Phetchaburi | 144,392 | 499 |
6. Phrachuap Khiri Khan | 191,306 | 488 |