Do

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

Arts, entertainment and media

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

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