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

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)
 * Range Officer, supervising a shooting range
 * 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