DB or db or dB may stand for:

• DB (car), a French automobile maker
• Decibel (dB)
• Deutsche Bahn, the major German railway company
• Deutsche Bank
• Dominion Breweries , a major beer brewing company of New Zealand
• Dubnium (Db), symbol for the chemical element
• A database
• The Db's - A New Wave band from the 1980's