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

Languages

* The English verb, ''do'', which may serve as an auxiliary verb; see do-support * Do (kana), ''Do'' (kana), a mora symbol in Japanese writing * Ditto mark

People

* Đỗ, a Vietnamese surname * Do (surname), includes people with the surname * D.O. (entertainer) (born 1993), South Korean singer and actor * D.O. (rapper), Canadian rapper * Do (singer) (born 1981), Dutch singer * Marshall Applewhite (1931–1997), American cult leader

Music

* The Dø, a French/Finnish indie pop band * Do (Do album), ''Do'' (Do album), an album by Dutch singer Do * Do (Psychostick album), ''Do'' (Psychostick album) * C (musical note), the first note of the musical scale in ''fixed do'' solfège * Delta Omicron, an international music fraternity * Do, the first syllable of the scale in solfège * Do, a type of buk (drum) used in Korean ritual music * "Do", a song by the White Stripes from the 1999 album The White Stripes (album), ''The White Stripes'' (album)

Science and medicine

* ''The DO'', an online magazine published by the American Osteopathic Association * Dansgaard–Oeschger event, in climate science * Delta Omega, an American public health honorary society * Doctor of Osteopathic Medicine * Dissolved oxygen

Technology

* .do, the country code top level domain for the Dominican Republic * Dornier Flugzeugwerke, a defunct German aircraft manufacturer * GNOME Do, an application launcher for Linux * Dō, the torso protection in a suit of bōgu, kendo armor

Places

* Do (province), the Korean and Japanese administrative division equivalent to the ancient Chinese dao * Do (administrative division), an administrative unit in both North and South Korea * Do, Stolac, Do (Berkovići), Bosnia and Herzegovina * Do (Hadžići), Bosnia and Herzegovina * Do, Stolac, Bosnia and Herzegovina * Do (Trebinje), Bosnia and Herzegovina * Do, Ivory Coast * Dominican Republic

Other uses

* DO (film), ''DO'' (film) * Dō (philosophy), a doctrine or lifestyle in Japanese and Korean cultures * Delivery order * Denominación de origen, a Spanish wine appellation * Directorate of Operations (CIA) of the United States Central Intelligence Agency * Dominicana de Aviación, a defunct Dominican airline * Do, the number twelve in the duodecimal system