Wai or WAI may refer to:
- Wai, Maharashtra, a town in India
- Wai, an alternative name for the Nuristani people, speakers of the Waigali language
- NO WAI, a phrase that is part of the O RLY? Internet meme.
- Wai, a form of Thai greeting
- Wai, a term referring to the walled villages of Hong Kong
- Wa (Japan) (倭), the Cantonese pronunciation of an ancient name of Japan, sometimes transcribed as Wai
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