Northern Thai language

Kam Mueang (Northern Thai: ᨣᩴᩤᨾᩮᩬᩥᨦ, กำเมือง ^ⓘ) or Northern Thai language (Thai: ภาษาไทยถิ่นเหนือ) is the language of the Northern Thai people of Lanna, Thailand. It is a Southwestern Tai language that is closely related to Tai Lue language. Kam Mueang has approximately six million speakers, most of whom live in the native Northern Thailand, with a smaller community of Lanna speakers in northwestern Laos.

Speakers of this language generally consider the name "Tai Yuan" to be pejorative. They refer to themselves as Khon Mueang (ᨤᩫ᩠ᨶᨾᩮᩬᩥᨦ, คนเมือง, [kʰon˧.mɯaŋ˧] – literally "people of Mueang" meaning "city dwellers"), Lanna, or Northern Thai. The language is also sometimes referred to as Phayap (พายัพ, Thai pronunciation: [pʰāː.jáp]), "Northwestern (speech)".

The term Yuan is still sometimes used for Northern Thai's distinctive Tai Tham alphabet, which is closely related to the old Tai Lue alphabet and the Lao religious alphabets. The use of the Tua Mueang, as the traditional alphabet is known, is now largely limited to Buddhist temples, where many old sermon manuscripts are still in active use. There is no active production of literature in the traditional alphabet, and when used in writing standard Thai script is invariably used. The modern spoken form is called Kam Mueang. There is a resurgence of interest in writing it in the traditional way, but the modern pronunciation differs from that prescribed in spelling rules.