RDN may refer to:

Radian Group (NYSE stock symbol), an American mortgage insurance company Radiodialnet (RDN.pe), communications and psychology department radio station for the University of San Martín de Porres Redang Airport (IATA airport code), Malaysia Reddish North railway station (National Rail station code), England Regional District of Nanaimo, on Vancouver Island, British Columbia, Canada Registered Dental Nurse Registered Dietitian Nutritionist, a qualified dietician Relative Distinguished Name, an identifier type in the LDAP internet protocol Robert De Niro Royal Danish Navy

See also Reverse domain name notation