RN or Rn may stand for:

  • rn (newsreader), a Usenet news client
  • RN the code for County Roscommon, Ireland
  • RN, the published memoirs of American President Richard Nixon
  • Air Horizons's IATA code
  • Fuerzas Armadas de la Resistencia Nacional, political party of El Salvador
  • Province of Rimini's ISO 3166-2:IT code
  • Radio National, an Australia-wide radio network broadcast by the Australian Broadcasting Corporation
  • Radon (symbol Rn), a chemical element
  • Regia Nave (Italian, meaning "Royal Ship"), a ship belonging to the Regia Marina
  • Registered Identification Number, a number issued by the Federal Trade Commission, used on clothing tags and labels
  • Registered nurse
  • Renovación Nacional or National Renewal (Chile), a Chilean political party
  • Resistencia Nacional of El Salvador
  • Rio Grande do Norte, ISO 3166-2:BR code of the Brazilian state
  • Round nose, a type of bullet
  • Royal Navy of the United Kingdom of Great Britain and Northern Ireland
  • Abbreviation for "right now".