The Tai-Kadai languages, also known simply as Kadai, are a language family found in Southeast Asia and southern China. They were formerly considered to be part of the Sino-Tibetan family, but are now classified independently as the Tai-Kadai family. They may be related to the Austronesian language family. Some researchers have even proposed they are part of a larger Austric superfamily.

The Tai-Kadai languages originated in southern China, which is home to most of the Tai-Kadai subfamilies. Speakers of the Tai languages subgroup moved south into Southeast Asia in historic times, founding the nations that later became Thailand and Laos.

Tai-Kadai languages

• Hlai languages (2)
  • Jiamao language (China)
  • Hlai language (China)
• Kadai languages (9)
  • Bu-Rong languages (1)
    • Yerong language (China)
  • Ge-Chi languages (3)
    • Gelao language (Vietnam)
    • Lachi language (Vietnam)
    • White Lachi language (Vietnam)
  • Yang-Biao languages (5)
    • Buyang language (China)
    • Cun language (China)
    • En language (Vietnam)
    • Laqua language (Vietnam)
    • Laha language (Vietnam)
• Kam-Tai languages (59)
  • Be-Tai languages (49)
    • Be languages (1)
      • Lingao language (China)
    • Tai-Sek languages (48)
      • Sek languages (1)
        • Saek language (Laos)
      • Tai languages (47)
  • Kam-Sui languages (9)
    • Ai-Cham language (China)
    • Cao Miao language (China)
    • Northern Dong language (China)
    • Southern Dong language (China)
    • Mak language (China)
    • Mulam language (China)
    • Maonan language (China)
    • Sui language (China)
    • T'en language (China)
  • Lakkja languages (1)
    • Lakkia language (China)