BWR or bwr may refer to:

• Benedict–Webb–Rubin equation, an equation of state used in fluid dynamics
• Black Warrior Review, a non-profit American literary magazine based at the University of Alabama
• Boiling water reactor, a type of light water nuclear reactor used for the generation of electrical power
• BWR, the Toronto Stock Exchange code for Breakwater Resources, a defunct Canadian mining company
• bwr, the ISO 639-3 code for Bura language, Nigeria