Ro or RO may refer to:

Look up RO, Ro, ro, or ro- in Wiktionary, the free dictionary.

• 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

• 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

• .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

• 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

• R0 (disambiguation)
• Rho (disambiguation)
• ROH (disambiguation)
• Roll-on/roll-off, ships designed to carry wheeled cargo

This disambiguation page lists articles associated with the title RO.
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