Answer: Majel Barrett
If it seems like every Starfleet ship and station in the Star Trek universe has a computer with the same voice, you’re not imagining things. Majel Barrett, the wife of Gene Roddenberry, was the voice of the computer in many of the original episodes of Star Trek as well as Star Trek: The Next Generation, Star Trek: Deep Space Nine, Star Trek: Voyager, five of the Star Trek films, two episodes of the prequel series Star Trek: Enterprise, and various computer games and software related to the franchise.
Barrett, Gene Roddenberry’s girlfriend at the time, appeared in Star Trek’s first pilot episode (“The Cage”) as the first officer, Number One. She then went on to voice the computer, appeared in the recurring role of Nurse Christine Chapel, and in later incarnations of the show, played the Betazoid ambassador Lwaxana Troi. Barrett was a lifelong fan and devotee of the show and never missed the chance to attend Star Trek conventions to spend time with fans. Barrett continued to work on material for the franchise over her entire life and completed the voice-acting work for 2009’s Star Trek relaunch just days before her death at the age of 76.