LWR may refer to:
- Livestock water recycling, a Canadian environmental company
- Light water reactor, a reactor used to generate nuclear power
- Lincolnshire Wolds Railway, a heritage railway in Lincolnshire, England
- Longwave radiation, infrared radiation emitted from the surface of the Earth
- Long Way Round, a motorcycle journey undertaken by Ewan McGregor and Charley Boorman
- Laser warning receiver, a military system used to detect laser emission of weapon guidance systems and laser rangefinders
- Lutheran World Relief, an international nonprofit organization specializing in International Development and Disaster Relief.