RBG may refer to:
- RBG: Revolutionary But Gangsta, a 2004 hip-hop album by duo Dead Prez
- RBG Resources, a British public-limited firm based in London
- RBG, the IATA identifier code for Roseburg Regional Airport, Oregon, USA
- Royal Botanical Gardens (disambiguation), several Royal Botanic Gardens or Royal Botanical Gardens
- Rhema Broadcasting Group, a New Zealand Christian media organization
- Red Barn Gallery, a photography gallery in Belfast, Northern Ireland
- Ruth Bader Ginsburg (born 1933), a United States Supreme Court justice
- Random blood glucose, a test for blood sugar
- Rubber band gun, a toy gun used to fire one or more rubber bands
- Random bit generator or Random number generator, a term used in computer science
- Regental Bahnbetriebs-GmbH, German railway company
- RBG Really Blown Glover KandEkreations.com