RSO or R.S.O. may refer to:
Roles and titles Range safety officer, a person responsible for the safe use of rocket vehicles Radiation Safety Officer, a person responsible for the safe use of radiation and radioactive materials Regional Security Officer, a Diplomatic Security Service Special Agent in charge of security at a US embassy Regional Security Office, office in a US embassy or consulate for the Diplomatic Security Service , Knight of the Order of the Sword Reconnaissance systems officer, operator of surveillance systems and equipment on a Lockheed SR-71 Blackbird aircraft
Organisations "Radio Symphony Orchestra", used by a number of orchestras: Danish National Symphony Orchestra, based in Denmark North German Radio Symphony Orchestra, based in Hamburg, Germany Stuttgart Radio Symphony Orchestra, based in Stuttgart, Germany Bavarian Radio Symphony Orchestra, based in Munich, Germany Frankfurt Radio Symphony Orchestra, based in Frankfurt, Germany Finnish Radio Symphony Orchestra Swedish Radio Symphony Orchestra Vienna Radio Symphony Orchestra Richardson Symphony Orchestra, based in Richardson, Texas Roanoke Symphony Orchestra, based in Roanoke, Virginia Rogers Sportsnet Ontario, a television station in Ontario, Canada RSO Records, a record label formed by Robert Stigwood in the late 1960s
Rohingya Solidarity Organisation, a political organization and former insurgent group in Myanmar (Burma)
Military technology Raupenschlepper, Ost, a fully tracked World War II German artillery tractor Radschlepper Ost, a wheeled World War II German artillery tractor
Other Railway Sub Office (1855–1905), a British Royal Mail office which received mail directly from rail transport Reactive Search Optimization, problem-solving methods with integrated online machine-learning capabilities Revised Statutes of Ontario, the provincial laws of Ontario, Canada Registered sex offender, a person listed on a sex offender registry Republic of South Ossetia, a partially recognised country in the South Caucasus Resident Space Object, any man-made object in Earth orbit no longer used by anyone Ryan Scott Oliver, an American musical theater songwriter RSO, musical duo consisting of American musician Richie Sambora and Australian musician Orianthi Rick Simpson Oil, a form of cannabis concentrate Red Star OS, also abbreviated as RSOS, is a North Korean operating system