RTN may refer to:
- Random telegraph noise
- Raytheon Company (stock symbol)
- Recursive transition network
- Register transfer notation, a type of specification language for synchronous digital circuits
- Reticular thalamic nucleus
- Retro Television Network, a television network in United States
- Return key
- Rotarian
- Routing transit number, a code used by the banking system in United States
- Royal Thai Navy
- RTN, the former callsign of the NRN TV station in Lismore, New South Wales, Australia
- Racetrack Television Network, a North American horse and greyhound racing network
- RTN (Switzerland), radio broadcaster