RO
# RO

Ro or RO may refer to:

## Organizations

* Ro (company), an American telehealth company
* Red Orchestra (espionage), a series of Soviet spy rings
* Reserve Officers' Training Corps, an American armed forces training program
* Royal Ordnance, a British armaments manufacturer
* Reach Out (non-profit), an Australian information website
* TAROM, a Romanian airline

## Places

* Rø, Denmark
* Ro, Emilia-Romagna, Italy
* Ro, Greece, a small Greek island
* Rö Church, in Stockholm County, Sweden
* Romania (ISO 3166-1 country code RO)
* Rondônia, Brazil

## Science and technology

* .ro, the top level internet domain for Romania
* Ro (antigen)
* Autoantigen Ro, a protein
* Ro (volume), an Egyptian unit of measurement
* Radio occultation, a technique for measuring the properties of an atmosphere
* Reactor operator, a person who controls a nuclear reactor
* Relaxation oscillator, an electronic oscillator
* Reverse osmosis, a filtration method
* Read-only access, a computer software attribute
* Receive only, a type of teleprinter
* Right only, a method of manipulating stereophonic sound

## Other

* Ro language, an a priori constructed language
* Ro (kana), a Japanese character
* Ro (title), a Fijian title of nobility
* Ro (video game), a 2008 IOS puzzle game
* Romanian language
* Ro (dubious Danish king)
* Ro (pharaoh) (fl. 32nd century BC), Egyptian pharaoh
* Ro (name)
* Renewables Obligation (United Kingdom), a British order requiring renewable electricity generation
* Restraining order, a legal injunction
* A shortened variety of the first name Rohit
* Residentie Orchestra, Dutch Orchestra based in Den Haag
* Rogue One, a 2016 Star Wars film
