Sai may be:

• Sai (great), destiny
• Sai (weapon), a weapon used in certain martial arts, of Okinawan origin
• Sai (game), a variant of the game Mancala.
• Sai, Aomori, a village in Aomori prefecture, Japan
• Sai, Orne, a commune in the département of Orne, France
• Social Accountability International, a U.S.-based, nonprofit organization dedicated to the development, implementation, and oversight of voluntary verifiable social accountability standards sa-intl.org
• The Chinese name for the Saka, tribes of eastern Scythia
• An alternate transliteration of Shai, a god of fate in Egyptian mythology
• A designation the Li people of China use for themselves
• A demon arts spell in the manga Bleach

People with the name Sai:

• Prince Sai, a Lao prince of Lan Xang
• Shirdi Sai Baba, a Hindu holy man of the 19th century. साई बाबा
• Sathya Sai Baba, a Hindu religious leader of Puttaparthi, India
• Fujiwara no Sai, a fictional character from the Japanese anime and manga Hikaru no Go
• Sai (Naruto), a character from the Japanese manga series Naruto who is Naruto's team member and rival, analogous to Sasuke.
• Sai, a respectful title for elders in Stephen King's "Dark Tower" series.

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