Thailand divides its settlements (thesaban) into three categories by size: city municipalities (thesaban nakhon), towns (thesaban mueang) and townships (or subdistrict municipality) (thesaban tambon). There are 33 city municipalities as of November 2024.

The national capital Bangkok and the special governed city Pattaya fall outside these divisions. They are "self-governing districts".

Due to the outdated nature of the thesaban system, any city municipality's growth subsequent to its settlement designation is not included in both area and population numbers. For this reason, the Department of Public Works and Town & Country Planning, and each province's Provincial Administrative Organization regularly revise and publish up-to-date city boundaries () to reflect population growth. These revisions are royally decreed and published in the Royal Thai Government Gazette. The term เขตเมือง/khet mueang can also be translated to the term urban area, a widely used term to describe and designate large cities.

Most Thai cities' revised boundaries are contained in the province's capital district, known as Amphoe Mueang. Chiang Mai is the only city outside Bangkok to cover multiple districts in its urban area. Bangkok and Chiang Mai are the only cities in Thailand with a population of over one million.

Thailand has an urbanization rate of 52% (2021), translating to 36,217,020 people of the total population. This rate is based on the thesaban system, meaning that 8,442,107 people live in city municipalities, 4,437,112 people live in town municipalities and 23,337,801 people in townships (subdistrict municipalities). According to the khet mueang system, 21,838,418 people (31.35% of total population) live in urban areas with a population greater than 150,000.

Several agencies issue population figures. Locally registered Thai populations are compiled by the Department of Local Administration (DLA). These figures are labeled as "Locally Registered Thai Population" and reflect the migrant, upcountry, and seasonal nature of Thai labor flows to the capital and tourist hot spots, yet maintain upcountry registration. Figures are very different from those by the National Statistics Office (NSO), which conducts the decennial census by attempting to count the total resident Thai population plus under 1,000 permanent resident foreigners. The result by the NSO is labeled as "Total Thai Population". Neither of the two offices release municipal level figures that include non-permanent residents, long-stay expatriates and figures for contracted foreign ASEAN migrants (a significant labor segment in cities like Bangkok, Pattaya, Chiang Mai, and Phuket, totaling two to three million workers), though this inclusion is being increasingly regularized since 2014. The NSO did release projected figures including regularized ASEAN migrants, i.e., "total resident population" down to the provincial level for 2017.

City municipalities

The table below lists Department of Local Administration (DLA) (local registered Thai) 2020 figures. For the NSO compiled total Thai resident decennial census municipal counts view here..

In most cases, municipal population numbers do not represent the current size of each individual city, but only the administrative core. Geographically limited city municipalities such as Koh Samui and the suburban city municipalities of Bangkok, namely Nonthaburi, Pak Kret, Samut Prakan, Nakhon Pathom, and Samut Sakhon, are the exception. Bangkok's suburban areas are inside the Bangkok Metropolitan Region and therefore do not have their own urban or metropolitan area. No. Name Thai District, Province Area Population Date, city designation1Krung Thep Maha Nakhon (Bangkok)กรุงเทพมหานคร 1,568.74 5,588,222 1972-12-142NonthaburiนนทบุรีMueang Nonthaburi, Nonthaburi 38.90 251,026 1995-09-233Pak Kretปากเกร็ดPak Kret, Nonthaburi36.04 189,458 2000-02-164Hat Yaiหาดใหญ่Hat Yai, Songkhla 21.00 149,459 1995-09-235Chaophraya Surasakเจ้าพระยาสุรศักดิ์Si Racha, Chonburi 276.98 146,474 2013-05-016Surat Thaniสุราษฎร์ธานีMueang Surat Thani, Surat Thani 68.97 131,599 2007-05-047Nakhon RatchasimaนครราชสีมาMueang Nakhon Ratchasima, Nakhon Ratchasima 37.50 122,730 1995-09-238Chiang Maiเชียงใหม่Mueang Chiang Mai, Chiang Mai 40.22 122,627 1936-03-289Udon ThaniอุดรธานีMueang Udon Thani, Udon Thani47.70 120,202 1995-09-2310PattayaพัทยาBang Lamung, Chonburi 53.44 117,606 1978-11-2911Khon Kaenขอนแก่นMueang Khon Kaen, Khon Kaen 46.00 110,615 1995-09-2312Nakhon Si ThammaratนครศรีธรรมราชMueang Nakhon Si Thammarat, Nakhon Si Thammarat 22.56 100,416 1994-08-1513Laem ChabangแหลมฉบังSi Racha, Chonburi 88.59 89,457 2010-05-2414RangsitรังสิตThanyaburi, Pathum Thani 20.80 84,268 2011-04-2915Nakhon Sawanนครสวรรค์Mueang Nakhon Sawan, Nakhon Sawan 27.87 81,239 1995-09-2316Phuketภูเก็ตMueang Phuket, Phuket 12.00 77,778 2004-02-1317Chiang RaiเชียงรายMueang Chiang Rai, Chiang Rai 60.85 77,545 2004-02-1318Ubon RatchathaniอุบลราชธานีMueang Ubon Ratchathani, Ubon Ratchathani 29.04 72,855 1999-03-0619Nakhon PathomนครปฐมMueang Nakhon Pathom, Nakhon Pathom 19.85 72,753 1999-11-0720Ko Samuiเกาะสมุย, Surat Thani 252.00 68,994 2012-09-1421Samut SakhonสมุทรสาครMueang Samut Sakhon, Samut Sakhon 10.33 65,409 1999-11-0722PhitsanulokพิษณุโลกMueang Phitsanulok, Phitsanulok 18.26 64,068 1999-03-0623RayongระยองMueang Rayong, Rayong 16.95 62,384 1999-11-0724SongkhlaสงขลาMueang Songkhla, Songkhla 9.27 60,021 1999-11-0725YalaยะลาMueang Yala, Yala 19.00 59,983 1995-09-2326TrangตรังMueang Trang, Trang 14.77 56,893 1999-11-0727Om Noiอ้อมน้อยKrathum Baen, Samut Sakhon 30.40 53,822 2010-11-1128Sakon NakhonสกลนครMueang Sakon Nakhon, Sakon Nakhon 54.54 51,331 2012-03-0829LampangลำปางMueang Lampang, Lampang 22.17 50,697 1999-11-0730Samut PrakanสมุทรปราการMueang Samut Prakan, Samut Prakan 7.33 49,604 1999-03-2331Phra Nakhon Si AyutthayaพระนครศรีอยุธยาPhra Nakhon Si Ayutthaya, Phra Nakhon Si Ayutthaya 14.84 49,208 1999-12-1432Mae Sotแม่สอดMae Sot, Tak 27.20 41,581 2010-01-2833Buriramบุรีรัมย์Mueang Buriram, Buriram 75.44 25,087 2024-10-31

Largest cities by urban population The following table lists the 10 largest cities in Thailand by urban population, based on Department of Local Administration (DLA) figures. These figures represent the current size of each city, accounting for area and population growth subsequent to each city's original city municipality designation.

Bangkok and Chiang Mai are the only cities covering multiple districts (known as Khet for Bangkok and Amphoe for the provinces), and the only two cities with a population of over one million. Although Pattaya is a "self-governing district" (located inside, but not part of Bang Lamung district), it has grown into all neighboring sub-districts and accounts for the largest population percentage, making it de facto a part of the "Pattaya-Bang Lamung-Jomtien" area. Chiang Mai is the only provincial city whose city boundaries () cover districts adjacent to the Amphoe Mueang district (Capital district). No.NameThaiProvinceAreaPopulation1Krung Thep Maha Nakhon (Bangkok)กรุงเทพมหานคร 1,568.74 10,539,0002Chiang Maiเชียงใหม่Chiang Mai 405 1,198,0003Nakhon RatchasimaนครราชสีมาNakhon Ratchasima 755.6 470,443 4Khon Kaenขอนแก่นKhon Kaen 953.4 418,221 5Hat Yaiหาดใหญ่Songkhla 852.796 406,601 6Udon ThaniอุดรธานีUdon Thani 1,094.7 397,374 7PattayaพัทยาChon Buri 727 354,169 8Chon BuriชลบุรีChon Buri 228.8 354,038 9Si RachaศรีราชาChon Buri 616.4 339,793 10RayongระยองRayong 514.5 292,743

Gallery of cityscapes

Town municipalities

Department of Local Administration (DLA) figures. The towns in bold characters are capitals.