Top 10 Largest Provinces in Thailand by Land Area

1. Chiang Mai

Chiang Mai is the largest province in Thailand, with a total area of 22,436.057 square kilometers. Previously ranked second after Nakhon Ratchasima, Chiang Mai rose to the top following the resolution of a boundary overlap issue between Mueang Gaa Subdistrict (Chiang Mai) and Ban Na Subdistrict (Tak), which added 125 square kilometers to its total area.

Most of Chiang Mai's land is mountainous, consisting of highlands and forested areas—particularly in the central, southern, and western regions, which account for over 70–80% of the total area. Flatlands, making up 10–20%, are found along major rivers like the Ping and Fang Rivers, running north to south.

Land Use:

Although it has the largest land area, much of Chiang Mai is forest conservation land or agricultural zones. Only about 4% of its land is used for urban development, mainly in Mueang District, San Sai, and Saraphi. The old city and surrounding areas near Wualai Road and Tha Phae Road are cultural preservation zones. The surrounding areas are dense to moderately dense residential and commercial zones, except around Payap University, which is designated for residential conservation.

2. Nakhon Ratchasima

Nakhon Ratchasima ranks second with 20,493.964 square kilometers. It features a diverse landscape: 30–40% flatlands in the north (e.g., Non Sung, Prathai, Phimai Districts) and 30–40% mountainous areas in the west and south (e.g., Pak Chong, Pak Thong Chai, Wang Nam Khiao). The remainder, including Mueang District, is moderately elevated.

Land Use:

About 68% of the land is used for agriculture, mainly sugarcane and cassava cultivation. Around 8% is urban land, mainly in Mueang and Pak Thong Chai Districts, particularly dense near Pak Canal. Surrounding areas consist of lower-density residential zones, including many housing developments. Industrial zones and warehouses are found in subdistricts like Khok Kruat, Sung Noen, Na Klang, Khok Thai, and Nong Bua Sala.

3. Kanchanaburi

Kanchanaburi has a total area of 19,483.148 square kilometers. The north is predominantly mountainous (60–70%), including districts like Sangkhla Buri, Thong Pha Phum, and Sai Yok. The northeastern districts, such as Lao Khwan and Bo Phloi, feature rolling plains, while the southern districts—Tha Maka, Tha Muang, and Mueang—are river basins.

Land Use:

Forests cover more than 60%, with agriculture taking up around 28%. Urban areas account for only 3%, mainly in Tha Maka, Tha Muang, and Mueang Districts. Densely populated residential zones are found along Sri Thamueang and Sri Loha Roads, while industrial and warehouse areas are located in Wang Khanai Subdistrict, especially around Soi Wang Khanai 16 and 19.

4. Tak

Tak is the fourth-largest province, with an area of 16,281.650 square kilometers. Over 70–80% of the area consists of mountains and highlands, particularly in the west, which is part of the Thongchai Mountain Range. The land gradually slopes toward the center and east, where large plains are found in Mueang, Ban Tak, Sam Ngao, and Wang Chao Districts.

Land Use:

Western urban areas are found in Mae Sot District, while eastern communities are located in subdistricts like Thung Kracho, Hua Diat, and Rahaeng. Most of the land is used for forestry, rural areas, and agriculture—especially along the Ping River, which is ideal for farming.

5. Ubon Ratchathani

Located in the easternmost part of Thailand, Ubon Ratchathani ranks fifth with 15,774.000 square kilometers. The province is characterized by gently sloping highlands and undulating plains, with only 10–20% mountainous areas. It is rich in rivers, including the Mun and Chi Rivers.

Land Use:

About 66% of the land is used for agriculture, mostly rice fields. Urban areas cover around 5.5%, concentrated in Mueang and Warin Chamrap Districts. These urban areas are used for both residential and commercial purposes and include Ubon Ratchathani International Airport.

6. Surat Thani

Surat Thani, the largest province in southern Thailand and sixth overall, covers 12,891.469 square kilometers. The west features part of the Phuket Mountain Range, while the east has highlands and flat coastal plains, which account for 40% of the area. The province includes hundreds of islands in the Gulf of Thailand, such as Koh Samui and Koh Phangan.

Land Use:

About 60% of the land is agricultural, mainly rubber and oil palm plantations. Urban areas make up 3–4%, found in districts like Phanom, Phrasaeng, Wiang Sa, Ban Na San, and Mueang. Industrial zones and warehouses are located in two areas: Khlong Tapan in Phunphin and Khlong Kadae in Karat Subdistrict, Kanchanadit.

7. Chaiyaphum

Chaiyaphum is the seventh-largest province, with 12,778.287 square kilometers. About 50% of the land consists of river plains and rolling terrain, while 40% is mountainous, primarily in the west.

Land Use:

Urban areas cover about 4%, scattered across Mueang, Nong Bua Rawe, Khon Sawan, Chatturat, and Bamnet Narong Districts. Surrounding these are 55% agricultural zones, mainly used for crops and rice farming.

8. Mae Hong Son

Mae Hong Son ranks eighth, covering 12,681.259 square kilometers. Over 80% of its terrain is made up of high mountains and complex valleys, especially in the east and central parts. Flat areas are limited and typically found along rivers like Pai and Yuam or within mountain valleys.

Land Use:

Over 90% of Mae Hong Son is designated forest conservation land. Agricultural and residential areas are sparsely distributed in a north-south axis through the province. In Mueang District, densely populated areas are located along major roads like Singhanat Bamrung, Khun Lum Praphat, and Makka Santi. Lower-density residential areas are in the outskirts, such as around Mae Hong Son Bus Terminal and certain neighborhoods like Pang Lor Nikom.

9. Phetchabun

With an area of 12,668.416 square kilometers, Phetchabun is the ninth-largest province. It is flanked by mountain ranges on both sides, with plains in the center (e.g., Mueang, Nong Phai, Bueng Sam Phan). The Pasak River runs from north to south, and while roads and an airport are present, there is no railway.

Land Use:

Around 57% of the land is agricultural, especially along the Pasak River. Forest conservation zones surround these areas, and urban communities are also located along the river in districts like Wichian Buri, Lom Sak, Nong Phai, and Mueang.

10. Lampang

Lampang has an area of 12,533.961 square kilometers and is often called “the city in the valley” due to its north–south mountain ranges enclosing central lowlands (20–30%). The geography resembles a basin, known as the “Lampang Basin.” The city center lies on elevated land.

Land Use:

About 70% of Lampang is forest, while 23% is used for agriculture. The most densely populated areas are around Chatchai Road and Round Wiang Road. Medium- to low-density zones are found in suburbs like Sop Tui and Phra Bat. The Wiang Nuea area is known as the old town, home to several temples and preserved as a cultural heritage zone.

These are Thailand’s 10 largest provinces by land area. Each province has its unique geographic and economic characteristics. For those looking to purchase land for housing or investment, these provinces present interesting opportunities. Larger land areas often mean more undeveloped plots at potentially lower prices than in major cities.