Phetchabun (Thai: เพชรบูรณ์, pronounced [pʰét.tɕʰā.būːn]) is one of Thailand's seventy-six provinces (changwat) and lies in lower northern Thailand. Neighbouring provinces are (from north clockwise) Loei, Khon Kaen, Chaiyaphum, Lopburi, Nakhon Sawan, Phichit and Phitsanulok.

Phetchabun is in the lower northern region of Thailand, in the area between the northern and the central region. The province lies in the broad fertile river valley of the Pa Sak River, with mountains of the Phetchabun mountain range to the east and west. The total forest area is 4,013 km (1,549 sq mi) or 32.5 percent of provincial area.

There are a total of four national parks, along with six other national parks, make up region 11 (Phitsanulok) of Thailand's protected areas.

• Thung Salaeng Luang National Park, 1,262 km (487 sq mi)
• Nam Nao National Park, 966 km (373 sq mi)
• Khao Kho National Park, 483 km (186 sq mi)
• Tat Mok National Park, 290 km (110 sq mi)

There are three wildlife sanctuaries, of which two are in region 11 (Phitsanulok) and Phu Luang is in region 8 (Khon Kaen) of Thailand's protected areas.

• Phu Luang Wildlife Sanctuary, 897 km (346 sq mi)
• Tabo–Huai Yai Wildlife Sanctuary, 654 km (253 sq mi)
• Phu Pha Daeng Wildlife Sanctuary, 235 km (91 sq mi)

Phetchabun especially Khao Kho is a place with good weather and cold all year round. Therefore, received the nickname "Switzerland of Thailand".

The word phetcha originates from the Sanskrit word vajra meaning "diamond" (or weapon of Indra), and the word bun from Sanskrit purna meaning "full", "perfect" or "whole". Hence the name of the province literally means "perfect diamond".

Initially, the province was called "Phe-cha-buth" as "Phuenchapura", which means the city that has plenty of crops. The reason is that the province is very fertile and has ample resources. Because of the fertility of the land, Phetchabun has always been agriculturally productive area.

Phetchabun was established by two kingdoms: the Sukhothai Kingdom, and the Ayutthaya Period of the King Narai.

In the Thesaphiban administrative reforms at the beginning of the 20th century, the province, together with Lom Sak province to the north, formed monthon Phetchabun. As it was the smallest monthon, it was also the first monthon to be dissolved in 1915, after being temporarily administered from Monthon Phitsanulok between 1903 and 1907. Lom Sak province was abolished and merged into Phetchabun in 1932.

From 1968–1982, communist insurgents established bases in the mountains in the province. From hidden locations they fought occasional skirmishes against the Thai Army.

The provincial seal shows a diamond on a mountain, as diamonds are found in the province. In the foreground are tobacco plants, as it is one of the crops grown in the province. The provincial tree is the tamarind. Craspedacusta sowerbyi, a rare species of freshwater jellyfish is the provincial aquatic animal. What with Phetchabun is one of the few places in the world, that is the habitat of this species of invertebrates.

Tourism is considered the main industry of the province.

Phu Thap Boek, the highest mountain in the province, is a well-known tourist destination. The area surrounding it is the largest cabbage-growing area in Thailand.

Phetchabun is 346 kilometres from Bangkok by using Highway 1 and Highway 21.

Phetchabun is served by Phetchabun Airport. Nok Air serves the airport with flights to Bangkok.

The province is divided into 11 districts (amphoe). These are further divided into 117 subdistricts (tambon) and 1261 villages (muban).

Mueang Phetchabun Chon Daen Lom Sak Lom Kao Wichian Buri Si Thep

Nong Phai Bueng Sam Phan Nam Nao Wang Pong Khao Kho

As of 26 November 2019, there are: one Phetchabun Provincial Administration Organisation (ongkan borihan suan changwat) and 25 municipal (thesaban) areas in the province. Phetchabun, Wichian Buri and Lom Sak have town (thesaban mueang) status. Further 22 subdistrict municipalities (thesaban tambon). The non-municipal areas are administered by 102 Subdistrict Administrative Organisations - SAO (ongkan borihan suan tambon).

Health	Education	Employment	Income
43	68	12	47
Housing	Family	Transport	Participation
28	44	41	47
Province Phetchabun, with an HAI 2022 value of 0.6337 is "somewhat low", occupies place 47 in the ranking.

Since 2003, United Nations Development Programme (UNDP) in Thailand has tracked progress on human development at sub-national level using the Human achievement index (HAI), a composite index covering all the eight key areas of human development. National Economic and Social Development Board (NESDB) has taken over this task since 2017.

Rank	Classification
1 - 13	"high"
14 - 29	"somewhat high"
30 - 45	"average"
46 - 61	"somewhat low"
62 - 77	"low"

Map with provinces and HAI 2022 rankings

• Sweet tamarind
• Arabica coffee
• Khao lam (sticky rice in bamboo)
• Black galingale
• Stevia tea
• Thai vermicelli rice noodles
• Cabbage
• Poultry
• Tobacco

• Saensak Muangsurin (b. 1950–2009), boxer
• Khaosai Galaxy (b. 1959), boxer, member of the International Boxing Hall of Fame
• Kaokor Galaxy (b. 1959), boxer
• Chana Porpaoin (b. 1966), boxer
• Songkram Porpaoin (b. 1966), boxer
• Sujin Naknayom (b. 1979), footballer
• Chakrit Buathong (b. 1985), footballer
• Sittisak Tarapan (b. 1984), footballer

• Phetchabun travel guide from Wikivoyage
• Phetchabun Tourist information
• Website of province (Thai)
• Maps & attractions in Phetchabun