DB may refer to:
In science and technology:
- Decibel (dB), a logarithmic unit of measurement in acoustics and electronics
- Dubnium (Db), a chemical element
- DB connector, a size of D-subminiature electrical connector
- Berkeley DB, a cross-platform embedded database library
- .db, a database file extension
In entertainment:
- D♭ (musical note)
- Daily Bugle, a fictional New York City newspaper
- The dB's, a power pop band from the 1980s
- DJ DB, a New York based drum 'n' bass dj
In locations:
- Daytona Beach, Florida
- Diamond Bar, California
- Discovery Bay, a residential development in Hong Kong
- Dobyns Bennett High School, a high school in Kingsport, Tennessee, USA
- Dâmboviţa County, a county in Romania, ISO 3166-2:RO code
In business:
- DB Breweries, a New Zealand company
- DB Medialab, a Norwegian online media company owned by the newspaper Dagbladet
- DB Records, a label in Atlanta, Georgia, USA
- Deutsche Bank, a German bank
- Diamond Bank of Nigeria
- Doing Business Report by the World Bank Group
- Defined benefit pension plan a scheme for retirement plans
In transportation:
- DB Draw, a bridge over the Passaic River, USA
- DB (car), a French automobile maker
- Deutsche Bundesbahn, the national railway company of the Federal Republic of Germany from 1949 until 1994
- Deutsche Bahn, the major German railway company since 1994
- David Brown (entrepreneur), one-time owner of car manufacturer Aston Martin, several of whose products carried his initials
- Dublin Bus, the principal bus operator in the Geater Dublin Area of Ireland
In other uses:
- db.no, the online version of the Norwegian newspaper Dagbladet
- ȸ, the db-digraph a ligature of "d" and "b" in African linguistics
- Defensive back, a position in American football and Canadian football
- dyne:bolic, a GNU/Linux distribution
- douche bag, a general insult, especially when texting or other communication media
- D. B. Cooper, a hijacker