Chiang Mai (, from Thai: เชียงใหม่ [tɕʰīəŋ màj] (listen), Northern Thai: ᨩ᩠ᨿᨦᩉ᩠ᨾᩲ᩵, เจียงใหม่ [t͡ɕīəŋ.màj] (listen)), sometimes written as Chiengmai or Chiangmai, is the largest city in northern Thailand, the capital of Chiang Mai province and the second largest city in Thailand. It is 700 km (435 mi) north of Bangkok in a mountainous region called the Thai highlands and has a population of 1.2 million people as of 2022, which is more than 66 percent of the total population of Chiang Mai province (1.8 million).

Chiang Mai (meaning "New City" in Thai) was founded in 1296 as the new capital of Lan Na, succeeding the former capital, Chiang Rai.^{: 208–209} The city's location on the Ping River (a major tributary of the Chao Phraya River) and its proximity to major trading routes contributed to its historic importance.

The city (thesaban nakhon, "city municipality") of Chiang Mai officially only covers most parts (40,2 km²) of the Mueang Chiang Mai district in the city centre and has a population of 127,000. This census area dates back to 1983 when Chiang Mai's municipal area was enlarged for the first and last time since becoming the first City Municipality in Thailand (then under Siam) in 1935. The city's sprawl has since extended into several neighboring districts, from Hang Dong in the south, to Mae Rim in the north, and Suthep in the west, to San Kamphaeng in the east, forming the Chiang Mai urban area with a size of 2,303 km².

The city municipality is subdivided into four khwaeng (electoral wards): Nakhon Ping, Sriwichai, Mengrai, and Kawila. The first three are on the west bank of the Ping River, and Kawila is on the east bank. Nakhon Ping District includes the northern part of the city. Sriwichai, Mengrai, and Kawila consist of the western, southern, and eastern parts, respectively. The city center—within the city walls—is mostly within Sriwichai ward.