Keir Dullea (kɪr duˈleɪ; born May 30, 1936) is an American actor perhaps best known for the character of astronaut David Bowman he portrayed in the 1968 film 2001: A Space Odyssey and in 1984's 2010: The Year We Make Contact.

Slim, remote and boyishly handsome, one of Keir Dullea's most arresting features were his pale blue eyes and, at one time, they were featured all over the screen in a number of watershed films of the 1960s. A major, up-and-coming film star from the Camelot years straight through to the turbulent Vietnam era, he never quite reached his peak and his star wattage began losing much of its power into the next decade. Instead he persevered on TV and the stage in a career now surpassing five decades. The Cleveland-born actor was the son of bookstore owners and raised in New York's Greenwich Village section. He graduated from George School in Pennsylvania and attended both Rutgers and San Francisco State before deciding to pursue summer stock and regional theatre. Attending the Neighborhood Playhouse, he made his New York debut in a 1956 production of "Sticks and Bones". His first big break came with the pilot of the "Route 66" series and proceeded to find other TV roles in "The Naked City", "Checkmate" and various dramatic showcase programs. Following stage work in "Season of Choice" (1959) and "A Short Happy Life" (1961), Keir made an auspicious dramatic film debut in a leading role with Hoodlum Priest (1961), playing a troubled street gang member who crosses paths with Don Murray (I)'s determined minister. The young actor's characters from then on seemed to walk a dangerous tightrope of emotions, and his apparent versatility at such a young age led him to a number of other psychologically scarred portrayals. Tending to play younger than he was, none were more disturbed than his aphephobic teenager David (Keir was 26 at the time) in the deeply-felt love story David and Lisa (1962). Paired beautifully with Janet Margolin's schizophrenic Lisa, the fair-haired actor won a Golden Globe for "Most Promising Male Newcomer". In the James Jones (I) WWII drama Thin Red Line, The (1964), Keir plays an edgy, nervous-eyed private who is push to his murderous brink by a brutal sergeant at Guadacanal. In Bunny Lake Is Missing (1965), he portrays the incestuously-inclined brother of Carol Lynley, who may or may not figure into the disappearance of Lynley's child. Keir also co-starred as the mysterious intruder who inserts an emotional wedge between lesbian lovers Anne Heywood and Sandy Dennis (I) in the landmark gay film Fox, The (1967). Topping it off he played the salacious Marquis De Sade himself in a relatively tame, internationally-flavored production of De Sade (1969). The apex of his film career, however, came with his lead participation in Stanley Kubrick's milestone epic 2001: A Space Odyssey (1968) as astronaut David Bowman. On the stage front, he made his Broadway debut in 1967 with "Dr. Cook's Garden" with Burl Ives, and won "flower power" stardom two years later as a sensitive blind youth who attempts to angle free of his protective, overbearing mother and pursue love with a free-spirited girl (Blythe Danner) in "Butterflies Are Free". By the time the movie version materialized in 1972, both stars were replaced by Oscar winner Goldie Hawn and up-and-comer Edward Albert. Keir then sought film work in England and Canada with lukewarm results. He continued to show his odd-man-out appeal on 1970s Broadway as Brick in the 1974 Broadway revival of "Cat on a Hot Tin Roof" opposite Elizabeth Ashley (I) Maggie, and in the dark comedy "P. S. Your Cat Is Dead!" a year later. He has since maintained a sturdy career on stage in New York City and in regional theaters with productions of "Sweet Prince", "The Seagull" and "The Little Foxes", among others. He has also continued to be an occasional presence on TV as a guest star on such shows as "Law & Order". Post-60s cinematic highlights include another mysterious stranger type in Next One, The (1984) and recreating his David Bowman role in the equally ambitious but less awe-inspiring "2001" sequel 2010 (1984). Married first to stage and film actress Margot Bennett (I), he and his third wife, Susie Fuller (whom he met during the London run of "Butterflies"), co-founded the Theater Artists Workshop of Westport, in 1983. Keir, his wife and her two stepchildren took up residence in London for quite some time. After his wife's death in 1998, Keir married a fourth time to actress Mia Dillon (best known for creating the role of Agnes in "Agnes of God" on Broadway), in 1999. Only weeks later they appeared together in a stage production of "Deathtrap". His more recent supporting work in films include the featured role of a senator in the Matt Damon/Angelina Jolie thriller _Good Shepherd, The (2006), directed by Robert De Niro.