American actor who played Dr. Leonard McCoy in The Original Series, The Animated Series and six films, and appeared in The Next Generation's premiere.
DeForest Kelley (1920–1999) was an American actor best known before Star Trek for supporting roles, often villains, in film and television westerns, including Gunfight at the O.K. Corral. Gene Roddenberry had wanted him for the series from early on.
Kelley joined the regular cast as Dr. Leonard McCoy from the first broadcast episode, The Man Trap, and played the irascible chief medical officer throughout the original series, in The Animated Series and in all six original-cast films. His character's humane, emotional arguments with Spock became one of the defining features of the series, with Kirk often caught between them.
In 1987 he made a cameo in the Next Generation premiere, Encounter at Farpoint, as an aged Admiral McCoy touring the new Enterprise, linking the two generations of the franchise. Star Trek VI: The Undiscovered Country (1991) was his final feature appearance as the character. He died in 1999.