A telegraphist (British English), telegrapher (American English), or telegraph operator is an operator who uses a telegraph key to send and receive the Morse code in order to communicate by land lines or radio.

During the Great War the Royal Navy enlisted many volunteers as radio telegraphists. Telegraphists were indispensable at sea in the early days of wireless telegraphy, and many young men were called to sea as professional radiotelegraph operators who were always accorded high-paying officer status at sea. Subsequent to the Titanic disaster and the Radio Act of 1912, the International Safety of Life at Sea (SOLAS) conventions established the 500kHz maritime distress frequency monitoring and mandated that all passenger-carrying ships carry licensed radio telegraph operators.