RDM may stand for:

In business:

• Rheinmetall Denel Munition, Military technology group - Germany.
• Rheinmetall Denel Munition South Africa, Military technology group - South Africa.
• Richardson Devine Marine, Australian shipbuilding company
• Rotterdamsche Droogdok Maatschappij, a shipbuilding and repair company in Rotterdam, the Netherlands
• Robust decision-making, a framework that helps identify and evaluate robust strategies under 'deep uncertainty'

In military:

• Radar Doppler Multifunction, a French stopgap radar for the Mirage 2000 fighter plane
• Radarman, a former rank of the United States Navy

In music:

• Rhythms del Mundo, a nonprofit salsa and mambo album by Cuban musicians
• Il Rovescio della Medaglia, an Italian symphonic rock band

In people:

• Robert Douglas McIntyre (1913-1998), Scottish nationalist politician
• Roberto Di Matteo (born 1970), Italian football player
• Ronald D. Moore (born 1964), American screenwriter and TV producer of Star Trek and Battlestar Galactica
• Roy D. Mercer, a prank-calling radio character
• Raphael Maklouf, British sculptor and designer of the third coinage portrait of Elizabeth II, sometimes known by his initials RDM

In technology:

• Rapid Development Methodology, software Iterative and incremental development process, developed by Lynn G. Gref and Dr. William Spuck
• Raw Disk Mapping, hard disk mapping for use by a virtual disk image
• RDM Server, a database platform from Raima Inc
• Red Digital Magazines, components of the REDCODE file format
• RDM (lighting), or Remote Device Management, an electronic protocol used in stage lighting
• Research data management, the organisation of research data, from its entry to the research cycle through to the dissemination and archiving of results
• Reference Data Management, the data used to categorize other data within applications and databases

In transportation:

• Riding Mill railway station (National Rail station code), Northumberland, England
• Roberts Field (IATA airport code), an airport in Redmond, Oregon