Grau is a German word meaning "gray" and a Catalan and Asturian word meaning "grade". It may refer to:
- BAP Almirante Grau (CLM-81), a De Zeven Provinciën class cruiser in service with the Peruvian Navy
- Grau Käse, Tyrolean grey cheese
- Grado, Italy, Grau in the Friulian language
- Grado, Spain, Grau in the Asturian language
- Grau is a German record label producing mostly Doom metal.
- GRAU is the Main Agency of Missiles and Artillery of the Ministry of Defense of the Russian Federation.