R13 or R-XIII may refer to:
Aviation Fouga CM.8 R13 Cyclone, a French sailplane Lublin R-XIII, a Polish army-cooperation plane Tumansky R-13, a Soviet turbojet engine
Roads Jalan Gua Kelam, in Malaysia R-13 regional road (Montenegro) R-13 Line, A Norwegian railroad line, running from Dal to Drammen
Other uses Caraga or Region 13, an administrative region in the Philippines R-13 or Restricted-13, a movie rating from the Movie and Television Review and Classification Board R13 (drug), an antidementia agent R-13 (missile), a Soviet missile system R13 (Rodalies de Catalunya), a regional rail line in Catalonia, Spain Chlorotrifluoromethane, a refrigerant Nyaneka language R13: Extremely flammable liquefied gas, a risk phrase Rebellion R13, a prototype racing car ROT13, a simple cipher , a submarine of the United States Navy R 13, a Buffet Crampon clarinet model