Do, DO or D.O. may refer to:

• Do (Do album), 2004
• Do (Psychostick album), 2018
• "Do", a song by the White Stripes from the 1999 album The White Stripes
• C (musical note), or Do
  • fixed do and movable do solfège
• Do, a type of buk drum in Korean ritual music
• The Dø, a French–Finnish indie pop band

• The DO, an online magazine of the American Osteopathic Association
• Wazir (film), 2016, working title Do

• Do-support, in English grammar, the use of the auxiliary verb do to form questions
• Do (kana), or To, a mora symbol in Japanese writing
• do., abbreviation for ditto

• Do (surname), including a list of people with the surname
  • Đỗ, a Vietnamese family name
• Do (singer) (Dominique Rijpma van Hulst, born 1981), Dutch singer
• D.O. (entertainer) (Doh Kyung-soo, born 1993), South Korean singer and actor
• D.O. (rapper) (a.k.a. Defy the Odds; Duane Gibson, fl. from 2000), Canadian rapper
• Marshall Applewhite (1931–1997), also known as Do, American cult leader

• Do (province), a Korean and Japanese administrative division
  • Do (administrative division), in North and South Korea
• Do, Stolac, Bosnia and Herzegovina
• Do (Hadžići), Bosnia and Herzegovina
• Do, Stolac, Bosnia and Herzegovina
• Do (Trebinje), Bosnia and Herzegovina
• Dô, a coalition of villages in modern-day Mali
• Do, Ivory Coast, or Doh
• Dominican Republic, ISO 3166 code DO

• Dansgaard–Oeschger event, or D–O event, in climate science
• Delta Omega, an American public health honorary society
• Dissolved oxygen, oxygen saturation in aquatic environments
• .do, the country code top level domain for the Dominican Republic
• Do, several aircraft models by Dornier Flugzeugwerke
• GNOME Do, an application launcher for Linux
• Dō, the torso protection in bōgu, kendo armour

• Dō (philosophy), a doctrine or lifestyle in Japanese and Korean cultures
• Denominación de origen, a geographical indication system for food and wine in Portugal, Spain and Latin America
• Directorate of Operations (CIA) of the United States Central Intelligence Agency
• Doctor of Osteopathic Medicine (DO)
• Dominicana de Aviación, a defunct Dominican airline, IATA code DO
• Do, the number twelve in the duodecimal system
• Delta Omicron, an international music fraternity

• D/O (disambiguation)
• D0 (disambiguation) (D followed by zero)
• Doe (disambiguation)
• Doo (disambiguation)
• Doh (disambiguation)
• Tao or Dao, the natural way of the universe, as conceived in East Asian philosophy and religion