RM or rm can mean:

• Research Machines plc
• RealMedia
• Resource management, a service in ATM networks
• Rhaeto-Romance language (ISO 639 alpha-2, rm)
• rm, a Unix command
• Return Missionary , LDS church
• The RM , a movie
• Regionalbahnen Mittelland AG, a Swiss railway company
• an abbreviation for the Malaysian ringgit
• Relative Migration in Gel electrophoresis