Kenneth Lavelle "K.L." Smith (26 October 1922 – 24 August 1981; age 58) was the actor who played the Klingon captain in the Star Trek: The Original Series third season episode "Elaan of Troyius". He filmed his scenes on Friday 31 May 1968 at Desilu Stage 9.
Smith made guest appearances on numerous television series, including Gunsmoke, Rawhide, The Untouchables, Wagon Train, Bonanza, The Virginian, and Gene Roddenberry's The Lieutenant (starring Gary Lockwood).
He and fellow Star Trek actors Leonard Nimoy, Lawrence Dobkin, and William Schallert had uncredited appearances in Them! (1954). Smith's other feature film credits include The Wild One (1953, starring Marlon Brando), Pushover (1954), Oh... Rosalinda!! (1955, with Jill Ireland), and Elvis Presley's Jailhouse Rock (1957, with Dick Dial and Noble Chissell) and Roustabout (1964, with Lance LeGault, Marianna Hill, Terri Garr, and Carey Foster).
Smith retired from acting in 1971. His last appearance was in The Delphi Bureau (1972, starring Star Trek V: The Final Frontier actor Laurence Luckinbill).