Who provided the voice of the Enterprise's computer in the original series?

Majel Barrett provided the voice of the Enterprise's computer in the original series. Her calm, measured delivery became one of Star Trek's most recognizable sounds, even though the computer was usually treated as an unseen shipboard system rather than a character with a personal identity.

Barrett was already part of Star Trek's early history. She played Number One in the first pilot, "The Cage," and later became Nurse Christine Chapel in the regular series. Her relationship with creator Gene Roddenberry also helped keep her closely connected to the franchise. In the original series, she voiced the Enterprise computer in several episodes, generally without on-screen credit.

The role continued far beyond the 1966–1969 series. Barrett supplied computer voices for later Star Trek productions, including The Next Generation, Deep Space Nine, Voyager, several films, and two episodes of Enterprise. This is why she is sometimes described as the voice of Starfleet computers generally, not merely the original Enterprise.

A common mix-up is confusing the computer voice with Nichelle Nichols, who played Lieutenant Uhura and occasionally handled communications. William Shatner, Leonard Nimoy, and Barrett's other Star Trek characters were not the voice being asked about here.