Communications officer, a special crewmember found onboard Federation Starfleet ships.

Comms officer is responsible for managing all incoming transmissions.

Starships of the mid to late 24th century did not have a bridge communications officer. Onboard the USS Enterprise-D the tactical officer doubled as communications officer, as did occasionally the operations manager.
 

Known Officers in this Department:

Ensign Hoshi Sato (Communications Officer USS Enterprise NX-01)
Lieutenant Uhura (Communications Officer USS Enterprise NCC-1701 to NCC-1701-B)
On other vessel the job off communications officer was often shared by the Tactical and Operations Officers.