HAI may refer to:

• Hai (surname), a variant on the Chinese surname Xǔ (許/许)
• Hoàng Hải (born 1982), Vietnamese singer
• Thanh Hải (1930–1980), Vietnamese poet

“Haï” is an essay written by French Nobel laureate J. M. G. Le Clézio.

Hái! is the fourth and final album to be released by British duo The Creatures, composed of former Siouxsie and the Banshees members Siouxsie Sioux and Budgie. The album was recorded in two parts: the drums were recorded by Budgie and Kodo drummer Leonard Eto in Tokyo in August 2002 and the rest of the recording was done in Europe. During their stay in Japan, the band was inspired and "touched by the delicate snowfall imagery of Akira Kurosawa's Ikiru (1952), absorbing the vibrancy of Tokyo's Roppongi district, and spiritualised by the ancient Shinto shrines and tranquil shores of Lake Ashi."