WI may refer to:

  • Wisconsin United States postal abbreviation
  • Wiesbaden, a city in southwest Germany
  • Watch Instantly, a video streaming service offered by Netflix
  • Waterfall Ice, the ice formed from a frozen waterfall
  • West Indies postal abbreviation
    • West Indies cricket team, a term used in cricket statistics
  • Women's Institutes, a locally organised group for British women

Wi may refer to:

  • Wi (kana), an obsolete Japanese character
  • Wi (mythology), a Lakota deity
  • Wi, Inc., an American medical device development corporation
  • Wiman, European surname
  • Wi Man of Gojoseon, ruler of Wiman Joseon
  • Wi, common of surname Wei (魏, 韋, 衛, 尉)