Iwai or IWAI may refer to:Iwai (surname) Iwai, Ibaraki, a city in Japan Iwai Station, a railway station in Minamibōsō, Chiba Prefecture, Japan Iwai Rebellion, a rebellion against the Yamato court that took place in Tsukushi Province, Japan I'wai, the culture hero of the Koko Y'ao in Australian Aboriginal mythology Inland Waterways Authority of India Inland Waterways Association of Ireland