Klingon_language The Klingon language (tlhIngan Hol in Klingon) is the constructed language spoken by Klingons in the fictional Star Trek universe. Deliberately designed by Marc Okrand to be "alien", it contains many peculiarities. The language's basic sound, along with a few words, was first devised by actor James Doohan ("Scotty") for Star Trek: The Motion Picture.