Lamphun (, ; Northern Thai: , ) is one of Thailand's seventy-six provinces (changwat), and lies in upper northern Thailand. Neighboring provinces are (from north clockwise) Chiang Mai, Lampang, and Tak.
Lamphun is in the Ping River valley. It is surrounded by mountain chains, with the Thanon Thong Chai Range in the west and the Khun Tan Range in the east of the province. It is some 670 kilometres north of Bangkok and 26 kilometres south of Chiang Mai. The total forest area is or 57.8 percent of the provincial area. Lamphun is regarded as the smallest province of northern region of Thailand.
There are three national parks, two of which are in region 16 (Chiang Mai) and Doi Chong in region 13 (Lampang branch), they are the protected areas in Lamphun province. (Visitors in fiscal year 2024)
The only wildlife sanctuary in region 13 (Lampang branch) is in Lamphun province.
Doi Pha Muang Wildlife Sanctuary
Under its old name of Haripunchai, Lamphun was the northernmost city of the Mon kingdom of the Dvaravati period, and also the last to fall to the Thai. In the late-12th century it came under siege from the Khmer, but did not fall. However, in 1281 King Mengrai of Lan Na finally seized the city, and made it part of his kingdom. After Burmese expansion in the 16th century, Lamphun was under Burmese rule for two centuries. In the 18th century, with the rise of Thonburi and Bangkok against Burmese rule, local leaders from Lampang agreed to be their allies. Lamphun was finally freed from the Burmese and ruled by relatives of Lampang's leader, gaining vassal status from Bangkok. Eventually, after the administrative reform of Bangkok government in the late-19th century, Lamphun became, as a province, a part of Siam.
The provincial seal shows the temple Wat Phra That Haripunchai, which was already the main temple of the city Lamphun during Mon times. The gold-covered chedi is said to contain a relic of Buddha.
The provincial flower is the Flame of the Forest (Butea monosperma), and the provincial tree is the Rain Tree (Samanea saman). The provincial aquatic life is the chubby frog (Glyphoglossus molossus).
The province is divided into eight districts (amphoes). These are further divided into 51 subdistricts (tambons) and 551 villages (mubans).
For national elections the province is divided into three constituencies. Constituency 1 covers the Mueang District except Tambon Makhuea Chae; Constituency 2 the districts Pa Sang, Mae Tha, and Tambon Makhuea Chae of Mueang District; and Constituency 3 the districts Ban Hong, Thung Hua Chang, and Li.
As of 26 November 2019 there are: one Lamphun Provincial Administration Organisation (') and 40 municipal (thesaban) areas in the province. Lamphun has town (thesaban mueang) status. Further there are 39 subdistrict municipalities (thesaban tambon). The non-municipal areas are administered by 17 Subdistrict Administrative Organisations - SAO (ongkan borihan suan tambon).
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.