An apparatus and method for speech recognition and character displaying in a mobile telecommunication system. In a speech recognition and character displaying apparatus for a mobile phone, an RF Module processes a signal received from a base station or to be transmitted to the base station by radio, a speech/character conversion table has conversion data for use in converting voice data to character data, a speech recognition and character conversion unit converts the voice signal received from the base station to voice data using speech recognition and the voice data to character data by referring to the speech/character conversion table, a display displays the converted character data, and a controller provides overall control to the mobile phone, transmits a speech recognition notification request message to the base station in a speech recognition and character display mode, and controls the speech recognition and character display operation.