Radioman (RM) was a rating for United States Navy and United States Coast Guard enlisted personnel, specializing in communications technology.

The rating was created originally in 1921. In 1998 the rating merged with the Data Processing Technician (DP) rating, retaining the Radioman designation until 1999 when it was redesignated Information Systems Technician (IT). Both Radiomen and Data Processing Technicians in the Navy had to undergo general rate training and take a computer-based exam in order to be designated under the new IT rating. In 1996, the Submarine force merged Radioman with Electronics Technicians/ Electronic Warfare Specialist. The Coast Guard rating was renamed Telecommunications Specialist (TC) in 1995, which split in July 2003 to make up the Information System Technician (IT) and Operations Specialist (OS) ratings.

The Radiomen of the US Navy were responsible for transmitting and receiving radio signals, and processing all forms of telecommunications through various transmission media aboard ships, aircraft and at shore facilities. This was done utilizing various frequencies in the ELF, VLF, LF, MF, HF, VHF, UHF, SHF and EHF spectrums. The type of circuits maintained included voice and data circuits between the ships of a battle group and allied units. Their duties also included message systems for generalized broadcasts and unit specific messages that were handled based on message priority and handling procedures. They were also responsible for the proper handling and destruction of classified material.

Radiomen were also responsible for periodic maintenance of the communications equipment, to include transmitters, receivers and antennas.

The positions generally found in the ship's 'Radio Shack' included -