Wo may refer to:

• Wo (kana), a Japanese kana
• Wolof language ISO 639-1 code
• Wa (Japan), an elder Chinese name for Japan
• Wo, the name of China Unicom's 3g network
• Wo Ding, traditionally believed to be a king of the Shang Dynasty
• Wo Jia, a king of the Shang Dynasty
• Wo Weihan (1949-2008), a Chinese scientist and entrepreneur executed for allegedly spying for Taiwan
• Wo Fat, a fictional nemesis of Steve McGarrett on the television show Hawaii 5-0
• Zhang Wo, a Chinese painter of the Yuan Dynasty

In British English, a walkover or W.O. is the awarding of a victory to a contestant because there are no other contestants, or because the other contestants have been disqualified or have ed. The term can apply in sport, but can also apply to elections. This is also typically referred to as winning "by default".