RDU can mean:
- Raleigh-Durham International Airport (IATA: RDU, ICAO: KRDU)
- the Raleigh-Durham, North Carolina metropolitan area
- RDU-FM, a New Zealand radio station
- Responsible drug use
- radiocommunication distribution undertaking, a type of repeater/broadcast translator
- In international law: Reservations, declarations, and understandings.