Tai Lue (New Tai Lü: ᦅᧄᦺᦑᦟᦹᧉ, Tai Tham: ᨣᩤᩴᨴᩱ᩠ᨿᩃᩨᩢ, kam tai lue, [kâm.tâj.lɯ̀]) or Xishuangbanna Dai is a Tai language of the Lu people, spoken by about 700,000 people in Southeast Asia. This includes 280,000 people in China (Yunnan), 200,000 in Burma, 134,000 in Laos, 83,000 in Thailand and 4,960 in Vietnam. The language is similar to other Tai languages and is closely related to Kham Mueang or Tai Yuan, which is also known as Northern Thai language. In Yunnan, it is spoken in all of Xishuangbanna Dai Autonomous Prefecture, as well as Jiangcheng Hani and Yi Autonomous County in Pu'er City.

In Vietnam, Tai Lue speakers are officially recognised as the Lự ethnic minority, although in China they are classified as part of the Dai people, along with speakers of the other Tai languages apart from Zhuang.

Tai Lue has 21 syllable-initial consonants, 9 syllable-finals and six tones (three different tones in checked syllables, six in open syllables).

The initials t͡s- and s- are palatalized before front vowels (which in the language are i, e, and ɛ) and become t͡ɕ- and ɕ-, respectively. For example, /t͡síŋ/ "hard" and /si᷄p/ "ten" are pronounced as [t͡ɕiŋ˥] and [ɕip˧˥] respectively. (Some textbooks denote t͡s as c).

Each vowel quality occurs in long-short pairs: these are distinct phonemes forming distinct words in Tai Lue.

Generally, vowels in open syllables (without codas) occur as long whereas ones in closed syllables are short (except /aː/ and /uː/).

Additionally, Tai Lue uses several diphthongs:

The table below presents six phonemic tones in unchecked syllables, i.e. closed syllables ending in sonorant sounds such as [m], [n], [ŋ], [w], and [j] and open syllables. There are six tones for unchecked syllables, although only three are allowed in checked syllables (those ending with -p, -t or -k).