Rao or RAO may refer to:
General
- Rao (surname), an Indian princely title cognate with Raja
- Rao is used as Tail name given to Kshatriyas of Maratha people in Maharastra
- Rao is also used as title of honour in Kamma caste of South India
- Rao Bahadur, a title of honour issued during the British rule in India to individuals who had performed great service to the nation
People and fictional characters
- Rao (surname), an Indian surname (family name), and male given (personal) name
- Rao (Chinese surname) (Ráo), a Chinese family name
- Rao (Greyhawk), the god of peace, reason, and serenity in the Dungeons & Dragons: World of Greyhawk campaign setting
- Raoh (Raō), a major antagonist in Fist of the North Star
- Rao a priestess in the video game "Okami"
Science
- Cramér–Rao bound, a statistical concept
- Rao–Blackwell theorem, a theorem in statistics
- Recent African Origin of modern humans, a paleoanthropological theory
- Recurrent airway obstruction (RAO), a respiratory disease in horses
- Response amplitude operator (RAO), a function relating a response to an input given the input frequency
Places
- Råö, a locality in Sweden
- Rao's, an Italian restaurant in New York City, USA
- Rao, West Sumatra, one of the districts of West Sumatra